boards: shields: Fix adafruit_2_8_tft_touch_v2 Arduino D4 pin (SDMMC CS)

The device tree overlay for the adafruit_2_8_tft_touch_v2 shield board
was incorrectly mapping the Arduino D4 pin, used for SDMMC chip select.

Signed-off-by: Maureen Helm <maureen.helm@nxp.com>
1 file changed