NFC: nfcmrvl_uart: fix device-node leak during probe

Make sure to release the device-node reference when done parsing the
node.

Fixes: e097dc62 ("NFC: nfcmrvl: add UART driver")
Cc: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>