firmware: arm_scmi: Suppress the driver's bind attributes

firmware: arm_scmi: Suppress the driver's bind attributes

[ Upstream commit fd96fbc8fad35d6b1872c90df8a2f5d721f14d91 ]

Suppress the capability to unbind the core SCMI driver since all the
SCMI stack protocol drivers depend on it.

Fixes: aa4f886f3893 ("firmware: arm_scmi: add basic driver infrastructure for SCMI")
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20221028140833.280091-2-cristian.marussi@arm.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>