crypto: arm64/poly1305 - move data to rodata section

When objtool gains support for ARM in the future, it may encounter issues
disassembling the following data in the .text section:
> .Lzeros:
> .long   0,0,0,0,0,0,0,0
> .asciz  "Poly1305 for ARMv8, CRYPTOGAMS by \@dot-asm"
> .align  2

Move it to .rodata which is a more appropriate section for read-only data.

There is a limit on how far the label can be from the instruction, hence
use "adrp" and low 12bits offset of the label to avoid the compilation
error.
Signed-off-by: Jia He <justin.he@arm.com>
Tested-by: Daniel Gomez <da.gomez@samsung.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

arch/arm64/crypto/poly1305-armv8.pl

@@ -473,7 +473,8 @@ poly1305_blocks_neon:
 	subs	$len,$len,#64
 	ldp	x9,x13,[$inp,#48]
 	add	$in2,$inp,#96
-	adr	$zeros,.Lzeros
+	adrp	$zeros,.Lzeros
+	add	$zeros,$zeros,#:lo12:.Lzeros
 
 	lsl	$padbit,$padbit,#24
 	add	x15,$ctx,#48
@@ -885,10 +886,13 @@ poly1305_blocks_neon:
 	ret
 .size	poly1305_blocks_neon,.-poly1305_blocks_neon
 
+.pushsection .rodata
 .align	5
 .Lzeros:
 .long	0,0,0,0,0,0,0,0
 .asciz	"Poly1305 for ARMv8, CRYPTOGAMS by \@dot-asm"
+.popsection
+
 .align	2
 #if !defined(__KERNEL__) && !defined(_WIN64)
 .comm	OPENSSL_armcap_P,4,4