lib/crc: arm64: Use existing macros for kernel-mode FPU cflags

Use the existing CC_FPU_CFLAGS and CC_NO_FPU_CFLAGS to pass the
appropriate compiler command line options for building kernel mode NEON
intrinsics code. This is tidier, and will make it easier to reuse the
code for 32-bit ARM.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260330144630.33026-9-ardb@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

Author: ardbiesheuvel

lib/crc/Makefile

@@ -39,9 +39,8 @@ crc64-y := crc64-main.o
 ifeq ($(CONFIG_CRC64_ARCH),y)
 CFLAGS_crc64-main.o += -I$(src)/$(SRCARCH)
 
-CFLAGS_REMOVE_arm64/crc64-neon-inner.o += -mgeneral-regs-only
-CFLAGS_arm64/crc64-neon-inner.o += -ffreestanding -march=armv8-a+crypto
-CFLAGS_arm64/crc64-neon-inner.o += -isystem $(shell $(CC) -print-file-name=include)
+CFLAGS_REMOVE_arm64/crc64-neon-inner.o += $(CC_FLAGS_NO_FPU)
+CFLAGS_arm64/crc64-neon-inner.o += $(CC_FLAGS_FPU) -march=armv8-a+crypto
 crc64-$(CONFIG_ARM64) += arm64/crc64-neon-inner.o
 
 crc64-$(CONFIG_RISCV) += riscv/crc64_lsb.o riscv/crc64_msb.o