tests/drivers: stm32l496g_disco: Enable ADC in tests.
tests/drivers: stm32l496g_disco: Enable ADC in tests.

This commit enables ADC test application to build and run on
stm32l496g_disco platform.

Signed-off-by: Affrin Pinhero <6fe933403e86d066e48dfd2d5ee140f71afeeee2@hcl.com>

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