firmware: arm_scmi: Convert u32 to unsigned long to align with arm_smccc_1_1_invoke()

All the parameters to arm_smccc_1_1_invoke() are unsigned long which
aligns well on both 32-bit and 64-bit Arm based platforms. Let us store
all the members in the structure scmi_smc used as the parameters to the
arm_smccc_1_1_invoke() call as unsigned long.

Cc: Cristian Marussi <cristian.marussi@arm.com>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20231009152049.1428872-1-sudeep.holla@arm.com


Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>