The scs_load and scs_save asm macros don't make use of the mandatory
'tmp' register argument, so drop it and fix up the callers.

Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20210527105529.21967-1-will@kernel.orgSigned-off-by: Will Deacon <will@kernel.org>