drivers: gpio: sam: Fix Kconfig default for SAM4L
drivers: gpio: sam: Fix Kconfig default for SAM4L

In update the Kconfig to depend on devicetree, the SAM4L
driver was missing a 'default y'.

Also remove unnecessary 'depends on GPIO'.

Signed-off-by: Kumar Gala <383ef5577c6e1178b93f59ec8d0936f76d2a98c4@kernel.org>

finikorg/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,galak/zephyr