firmware: arm_scmi: Ensure drivers provide a probe function

stable inclusion
from stable-5.10.57
commit 93ef561406a712b32e9a2203b406877081fa0df7
bugzilla: 176179 https://gitee.com/openeuler/kernel/issues/I4DZ64

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=93ef561406a712b32e9a2203b406877081fa0df7

--------------------------------

commit 5e469dac upstream.

The bus probe callback calls the driver callback without further
checking. Better be safe than sorry and refuse registration of a driver
without a probe function to prevent a NULL pointer exception.

Link: https://lore.kernel.org/r/20210624095059.4010157-2-sudeep.holla@arm.com


Fixes: 933c5044 ("firmware: arm_scmi: add scmi protocol bus to enumerate protocol devices")
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Cristian Marussi <cristian.marussi@arm.com>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>