Fix compilation failure, when Thumb support is not enabled:

arch/arm/kernel/entry-armv.S: Assembler messages:
arch/arm/kernel/entry-armv.S:501: Error: backward ref to unknown label "2:"
arch/arm/kernel/entry-armv.S:502: Error: backward ref to unknown label "3:"
make[2]: *** [arch/arm/kernel/entry-armv.o] Error 1
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>