ARM: tegra: fix build error when THUMB2_KERNEL enabled

This patch fix the build failure when CONFIG_THUBM2_KERNEL enabled. You
clould see the error message below:

arch/arm/mach-tegra/sleep-tegra30.S:69: Error: shift must be constant --
`orr r12,r12,r4,lsl r3'

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>