smccc: fix sign bit expansion

smccc: fix sign bit expansion

Signed ARM_SMCCC_FAST_CALL value is shifted to 31'st bit. Then, it is expanded
to 64 bit value, which results in 1s in higher 32 bits.

This causes corrupted values in 64-bit SMC IDs and issues in buggy handlers of
32-bit calls.

We need to make ARM_SMCCC_FAST_CALL unsigned long, so it would work properly
on 32 bit architectures.

Signed-off-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org>