include/linux/arm-smccc.h: avoid sign extension problem

include/linux/arm-smccc.h: avoid sign extension problem

Prior to this patch the ARM_SMCCC_FAST_CALL constant was of an unsigned
type causing unwanted sign extension. This patch explicitly selects an
unsigned type for the constant.

Reviewed-by: Pascal Brand <pascal.brand@linaro.org>
Tested-by: Jens Wiklander <jens.wiklander@linaro.org> (QEMU Aarch64)
Reported-by: Saksham Jain <sakjain92@gmail.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
From https://github.com/linaro-swg/linux.git
(cherry picked from commit 253e93086578d3f737cd16e79efb95cc6a833195)