arm64: entry: remove test_irqs_unmasked macro

We haven't needed the test_irqs_unmasked macro since commit:

  105fc335 ("arm64: entry: move el1 irq/nmi logic to C")

... and as we convert more of the entry logic to C it is decreasingly
likely we'll need it in future, so let's remove the unused macro.

There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210323181201.18889-1-mark.rutland@arm.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/kernel/entry.S

@@ -499,20 +499,6 @@ tsk	.req	x28		// current thread_info
 	irq_stack_exit
 	.endm
 
-#ifdef CONFIG_ARM64_PSEUDO_NMI
-	/*
-	 * Set res to 0 if irqs were unmasked in interrupted context.
-	 * Otherwise set res to non-0 value.
-	 */
-	.macro	test_irqs_unmasked res:req, pmr:req
-alternative_if ARM64_HAS_IRQ_PRIO_MASKING
-	sub	\res, \pmr, #GIC_PRIO_IRQON
-alternative_else
-	mov	\res, xzr
-alternative_endif
-	.endm
-#endif
-
 	.macro	gic_prio_kentry_setup, tmp:req
 #ifdef CONFIG_ARM64_PSEUDO_NMI
 	alternative_if ARM64_HAS_IRQ_PRIO_MASKING