arm64: Remove enable_daif macro

Since commit bb8e93a2 ("arm64: entry: convert SError handlers to C"),
the enable_daif assembler macro is no longer used anywhere, so remove it.
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20240229132802.1682026-2-ruanjinjie@huawei.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/include/asm/assembler.h

@@ -38,10 +38,6 @@
 	msr	daifset, #0xf
 	.endm
 
-	.macro enable_daif
-	msr	daifclr, #0xf
-	.endm
-
 /*
  * Save/restore interrupts.
  */