Add gpio in board yaml file, gpio2 is enabled by default.
Add btn and led nodes to ensure the button and blinky samples can work.
Add board overlay file for driver test case: gpio_basic_api.
Signed-off-by: Zongchun Yu <zongchun.yu@nxp.com>
The i.MX 91 Evaluation Kit (MCIMX91-EVK board) is a platform designed
to display the most commonly used features of the i.MX 91 applications
processor. The MCIMX91-EVK board is an entry-level development board
with a small and low-cost package.
Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>