firmware: smccc: Drop smccc_version enum and use ARM_SMCCC_VERSION_1_x instead

firmware: smccc: Drop smccc_version enum and use ARM_SMCCC_VERSION_1_x instead

Instead of maintaining 2 sets of enums/macros for tracking SMCCC version,
let us drop smccc_version enum and use ARM_SMCCC_VERSION_1_x directly
instead.

This is in preparation to drop smccc_version here and move it separately
under drivers/firmware/smccc.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Etienne Carriere <etienne.carriere@st.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Etienne Carriere <etienne.carriere@st.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20200518091222.27467-5-sudeep.holla@arm.com
Signed-off-by: Will Deacon <will@kernel.org>