arm64: use local label prefixes for __reg_num symbols

The __reg_num_xNN symbols that are used to implement the msr_s and
mrs_s macros are recorded in the ELF metadata of each object file.
This does not affect the size of the final binary, but it does clutter
the output of tools like readelf, i.e.,

  $ readelf -a vmlinux |grep -c __reg_num_x
  50976

So let's use symbols with the .L prefix, these are strictly local,
and don't end up in the object files.

  $ readelf -a vmlinux |grep -c __reg_num_x
  0
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/include/asm/sysreg.h

@@ -196,16 +196,16 @@
 #ifdef __ASSEMBLY__
 
 	.irp	num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30
-	.equ	__reg_num_x\num, \num
+	.equ	.L__reg_num_x\num, \num
 	.endr
-	.equ	__reg_num_xzr, 31
+	.equ	.L__reg_num_xzr, 31
 
 	.macro	mrs_s, rt, sreg
-	.inst	0xd5200000|(\sreg)|(__reg_num_\rt)
+	.inst	0xd5200000|(\sreg)|(.L__reg_num_\rt)
 	.endm
 
 	.macro	msr_s, sreg, rt
-	.inst	0xd5000000|(\sreg)|(__reg_num_\rt)
+	.inst	0xd5000000|(\sreg)|(.L__reg_num_\rt)
 	.endm
 
 #else
@@ -214,16 +214,16 @@
 
 asm(
 "	.irp	num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30\n"
-"	.equ	__reg_num_x\\num, \\num\n"
+"	.equ	.L__reg_num_x\\num, \\num\n"
 "	.endr\n"
-"	.equ	__reg_num_xzr, 31\n"
+"	.equ	.L__reg_num_xzr, 31\n"
 "\n"
 "	.macro	mrs_s, rt, sreg\n"
-"	.inst	0xd5200000|(\\sreg)|(__reg_num_\\rt)\n"
+"	.inst	0xd5200000|(\\sreg)|(.L__reg_num_\\rt)\n"
 "	.endm\n"
 "\n"
 "	.macro	msr_s, sreg, rt\n"
-"	.inst	0xd5000000|(\\sreg)|(__reg_num_\\rt)\n"
+"	.inst	0xd5000000|(\\sreg)|(.L__reg_num_\\rt)\n"
 "	.endm\n"
 );