powerpc: Align TOC to 256 bytes

[ Upstream commit 5e95235c ]

Recent toolchains force the TOC to be 256 byte aligned. We need
to enforce this alignment in our linker script, otherwise pointers
to our TOC variables (__toc_start, __prom_init_toc_start) could
be incorrect.

If they are bad, we die a few hundred instructions into boot.

Cc: stable@vger.kernel.org
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

arch/powerpc/kernel/vmlinux.lds.S

@@ -213,6 +213,7 @@ SECTIONS
 		*(.opd)
 	}
 
+	. = ALIGN(256);
 	.got : AT(ADDR(.got) - LOAD_OFFSET) {
 		__toc_start = .;
 #ifndef CONFIG_RELOCATABLE