firmware: arm_scmi: Drop OF node reference in the transport channel setup

firmware: arm_scmi: Drop OF node reference in the transport channel setup

The OF node reference obtained from of_parse_phandle() should be dropped
if node is not compatible with arm,scmi-shmem.

Fixes: 507cd4d2c5eb ("firmware: arm_scmi: Add compatibility checks for shmem node")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20230719061652.8850-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>