rpi_firmware_get() take reference, we need to release it in error paths
as well. Use devm_rpi_firmware_get() helper to handling the resources.
Also remove the existing rpi_firmware_put().

Fixes: 0b9f28fe ("Input: add official Raspberry Pi's touchscreen driver")
Fixes: 3b8ddff7 ("input: raspberrypi-ts: Release firmware handle when not needed")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
Link: https://lore.kernel.org/r/20221223074657.810346-1-linmq006@gmail.comSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>