ARM: 8867/1: vdso: pass --be8 to linker if necessary

ARM: 8867/1: vdso: pass --be8 to linker if necessary

The commit 1ceafb8c256b ("ARM: 8858/1: vdso: use $(LD) instead of $(CC)
to link VDSO") removed the passing of CFLAGS, since ld doesn't take
those directly. However, prior, big-endian ARM was relying on gcc to
translate its -mbe8 option into ld's --be8 option. Lacking this, ld
generated be32 code, making the VDSO generate SIGILL when called by
userspace.

This commit passes --be8 if CONFIG_CPU_ENDIAN_BE8 is enabled.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>