ARM: 8929/1: use APSR_nzcv instead of r15 as mrc operand

LLVM's integrated assembler does not accept r15 as mrc operand.
  arch/arm/boot/compressed/head.S:1267:16: error: operand must be a register in range [r0, r14] or apsr_nzcv
  1: mrc p15, 0, r15, c7, c14, 3 @ test,clean,invalidate D cache
                 ^

Use APSR_nzcv instead of r15. The GNU assembler supports this
syntax since binutils 2.21 [0].

[0] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;a=commit;h=db472d6ff0f438a21b357249a9b48e4b74498076

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

arch/arm/boot/compressed/head.S

@@ -1273,7 +1273,7 @@ iflush:
 __armv5tej_mmu_cache_flush:
 		tst	r4, #1
 		movne	pc, lr
-1:		mrc	p15, 0, r15, c7, c14, 3	@ test,clean,invalidate D cache
+1:		mrc	p15, 0, APSR_nzcv, c7, c14, 3	@ test,clean,invalidate D cache
 		bne	1b
 		mcr	p15, 0, r0, c7, c5, 0	@ flush I cache
 		mcr	p15, 0, r0, c7, c10, 4	@ drain WB

arch/arm/mm/proc-arm1026.S

@@ -138,7 +138,7 @@ ENTRY(arm1026_flush_kern_cache_all)
 	mov	ip, #0
 __flush_whole_cache:
 #ifndef CONFIG_CPU_DCACHE_DISABLE
-1:	mrc	p15, 0, r15, c7, c14, 3		@ test, clean, invalidate
+1:	mrc	p15, 0, APSR_nzcv, c7, c14, 3		@ test, clean, invalidate
 	bne	1b
 #endif
 	tst	r2, #VM_EXEC
@@ -363,7 +363,7 @@ ENTRY(cpu_arm1026_switch_mm)
 #ifdef CONFIG_MMU
 	mov	r1, #0
 #ifndef CONFIG_CPU_DCACHE_DISABLE
-1:	mrc	p15, 0, r15, c7, c14, 3		@ test, clean, invalidate
+1:	mrc	p15, 0, APSR_nzcv, c7, c14, 3		@ test, clean, invalidate
 	bne	1b
 #endif
 #ifndef CONFIG_CPU_ICACHE_DISABLE

arch/arm/mm/proc-arm926.S

@@ -131,7 +131,7 @@ __flush_whole_cache:
 #ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
 	mcr	p15, 0, ip, c7, c6, 0		@ invalidate D cache
 #else
-1:	mrc	p15, 0, r15, c7, c14, 3 	@ test,clean,invalidate
+1:	mrc	p15, 0, APSR_nzcv, c7, c14, 3 	@ test,clean,invalidate
 	bne	1b
 #endif
 	tst	r2, #VM_EXEC
@@ -358,7 +358,7 @@ ENTRY(cpu_arm926_switch_mm)
 	mcr	p15, 0, ip, c7, c6, 0		@ invalidate D cache
 #else
 @ && 'Clean & Invalidate whole DCache'
-1:	mrc	p15, 0, r15, c7, c14, 3 	@ test,clean,invalidate
+1:	mrc	p15, 0, APSR_nzcv, c7, c14, 3 	@ test,clean,invalidate
 	bne	1b
 #endif
 	mcr	p15, 0, ip, c7, c5, 0		@ invalidate I cache