Documentation: hid: intel-ish-hid: Document PRODUCT_FAMILY firmware matching

Document the ISH firmware filename matching rules, including the
new PRODUCT_FAMILY-based patterns and their search order.

This aligns the documentation with the driver behavior and provides
clear guidance for vendors supplying custom ISH firmware.

Signed-off-by: Vishnu Sankar <vishnuocv@gmail.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

Author: vishnuocv

Documentation/hid/intel-ish-hid.rst

@@ -413,23 +413,32 @@ Vendors who wish to upstream their custom firmware should follow these guideline
 
 - The firmware filename should use one of the following patterns:
 
+  - ``ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_FAMILY_CRC32}_${PRODUCT_NAME_CRC32}_${PRODUCT_SKU_CRC32}.bin``
+  - ``ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_FAMILY_CRC32}_${PRODUCT_SKU_CRC32}.bin``
+  - ``ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_FAMILY_CRC32}_${PRODUCT_NAME_CRC32}.bin``
+  - ``ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_FAMILY_CRC32}.bin``
   - ``ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_NAME_CRC32}_${PRODUCT_SKU_CRC32}.bin``
   - ``ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_SKU_CRC32}.bin``
   - ``ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_NAME_CRC32}.bin``
   - ``ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}.bin``
 
 - ``${intel_plat_gen}`` indicates the Intel platform generation (e.g., ``lnlm`` for Lunar Lake) and must not exceed 8 characters in length.
 - ``${SYS_VENDOR_CRC32}`` is the CRC32 checksum of the ``sys_vendor`` value from the DMI field ``DMI_SYS_VENDOR``.
+- ``${PRODUCT_FAMILY_CRC32}`` is the CRC32 checksum of the ``product_family`` value from the DMI field ``DMI_PRODUCT_FAMILY``.
 - ``${PRODUCT_NAME_CRC32}`` is the CRC32 checksum of the ``product_name`` value from the DMI field ``DMI_PRODUCT_NAME``.
 - ``${PRODUCT_SKU_CRC32}`` is the CRC32 checksum of the ``product_sku`` value from the DMI field ``DMI_PRODUCT_SKU``.
 
 During system boot, the ISH Linux driver will attempt to load the firmware in the following order, prioritizing custom firmware with more precise matching patterns:
 
-1. ``intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_NAME_CRC32}_${PRODUCT_SKU_CRC32}.bin``
-2. ``intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_SKU_CRC32}.bin``
-3. ``intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_NAME_CRC32}.bin``
-4. ``intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}.bin``
-5. ``intel/ish/ish_${intel_plat_gen}.bin``
+1. ``intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_FAMILY_CRC32}_${PRODUCT_NAME_CRC32}_${PRODUCT_SKU_CRC32}.bin``
+2. ``intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_FAMILY_CRC32}_${PRODUCT_SKU_CRC32}.bin``
+3. ``intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_FAMILY_CRC32}_${PRODUCT_NAME_CRC32}.bin``
+4. ``intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_FAMILY_CRC32}.bin``
+5. ``intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_NAME_CRC32}_${PRODUCT_SKU_CRC32}.bin``
+6. ``intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_SKU_CRC32}.bin``
+7. ``intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_NAME_CRC32}.bin``
+8. ``intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}.bin``
+9. ``intel/ish/ish_${intel_plat_gen}.bin``
 
 The driver will load the first matching firmware and skip the rest. If no matching firmware is found, it will proceed to the next pattern in the specified order. If all searches fail, the default Intel firmware, listed last in the order above, will be loaded.