uniphier: move ROTPK hash to .rodata section

This is not executable code.  It should be put into .rodata instead
of .text section.

This produces more correct BL1 image when SEPARATE_CODE_AND_RODATA is
defined.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

plat/socionext/uniphier/uniphier_rotpk.S

@@ -6,6 +6,7 @@
 
 	.global uniphier_rotpk_hash
 	.global uniphier_rotpk_hash_end
+	.section .rodata.uniphier_rotpk_hash, "a"
 uniphier_rotpk_hash:
 	/* DER header */
 	.byte 0x30, 0x31, 0x30, 0x0D, 0x06, 0x09, 0x60, 0x86, 0x48