firmware: arm_scmi: Simplify enable/disable clock operations

firmware: arm_scmi: Simplify enable/disable clock operations

SCMI clock enable/disable operations come in 2 different flavours which
simply just differ in how the underlying SCMI transactions is carried on:
atomic or not.

Currently we expose such SCMI operations through 2 distinctly named
wrappers, that, in turn, are wrapped into another couple of similarly and
distinctly named callbacks inside SCMI clock driver user.

Reduce the churn of duplicated wrappers by adding a param to SCMI clock
enable/disable operations to ask for atomic operation while removing the
_atomic version of such operations.

No functional change.

CC: Michael Turquette <mturquette@baylibre.com>
CC: Stephen Boyd <sboyd@kernel.org>
CC: linux-clk@vger.kernel.org
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20230826125308.462328-2-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>