x86: coral: Update the SD card-detect GPIO

Since the recent bug fix, it doesn't matter which GPIO phandle is used so
long as the GPIO number is right. Still, we may as well use the correct
one to avoid confusion.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>