[PATCH v1] arm64/sysreg: Remove unused define ARM64_FEATURE_FIELD_BITS

[Ben Horgan]

The define ARM64_FEATURE_FIELD_BITS is now unused and feature id
fields don't always have 4 bits. Remove it.

Signed-off-by: Ben Horgan <ben.horgan at arm.com>
---
It is still used in tools/testing/selftests/kvm/arm64/set_id_regs.c
but this uses the define in tools/arch/arm64/include/asm/sysreg.h.
I have submitted a separate patch to remove it from these as well:

https://lore.kernel.org/kvmarm/20251125101207.1492580-2-ben.horgan@arm.com/

Based on Linux 6.18-rc4
---
 arch/arm64/include/asm/sysreg.h | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index c231d2a3e515..1f3303d09a27 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -1129,8 +1129,6 @@
 #define gicr_insn(insn)			read_sysreg_s(GICV5_OP_GICR_##insn)
 #define gic_insn(v, insn)		write_sysreg_s(v, GICV5_OP_GIC_##insn)
 
-#define ARM64_FEATURE_FIELD_BITS	4
-
 #ifdef __ASSEMBLY__
 
 	.macro	mrs_s, rt, sreg
-- 
2.43.0