firmware: arm_scpi: remove two unneeded devm_kfree's in scpi_remove

Both memory areas are free'd anyway when the device is destroyed,
so we don't have to do it manually.

Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>