hwspinlock: remove now unused pdata from header file

The last user turned out to be obsolete and was removed. Remove the
unused struct now, too.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Link: https://lore.kernel.org/r/20260401071141.4718-3-wsa+renesas@sang-engineering.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

Author: Wolfram Sang

include/linux/hwspinlock.h

@@ -25,34 +25,6 @@ struct hwspinlock;
 struct hwspinlock_device;
 struct hwspinlock_ops;
 
-/**
- * struct hwspinlock_pdata - platform data for hwspinlock drivers
- * @base_id: base id for this hwspinlock device
- *
- * hwspinlock devices provide system-wide hardware locks that are used
- * by remote processors that have no other way to achieve synchronization.
- *
- * To achieve that, each physical lock must have a system-wide id number
- * that is agreed upon, otherwise remote processors can't possibly assume
- * they're using the same hardware lock.
- *
- * Usually boards have a single hwspinlock device, which provides several
- * hwspinlocks, and in this case, they can be trivially numbered 0 to
- * (num-of-locks - 1).
- *
- * In case boards have several hwspinlocks devices, a different base id
- * should be used for each hwspinlock device (they can't all use 0 as
- * a starting id!).
- *
- * This platform data structure should be used to provide the base id
- * for each device (which is trivially 0 when only a single hwspinlock
- * device exists). It can be shared between different platforms, hence
- * its location.
- */
-struct hwspinlock_pdata {
-	int base_id;
-};
-
 #ifdef CONFIG_HWSPINLOCK
 
 int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev,