ARM: 7333/2: jump label: detect %c support for ARM

Some versions of ARM GCC which do support asm goto, do not support
the %c specifier.  Since we need the %c to support jump labels
on ARM, detect that too in the asm goto detection script to avoid
build errors with these versions.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48637



Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>