boards: fix dependency for LV_COLOR_SWAP_16 to use configdefault

Use configdefault when enabling LV_COLOR_SWAP_16 within boards and
shield definitions, to avoid OR'ing the dependencies for the Kconfig
symbol. Otherwise, a user manually selecting LV_COLOR_DEPTH will
encounter build errors as LV_COLOR_SWAP_16 may be enabled when
LV_COLOR_DEPTH_16 is not selected

Fixes #81546

Signed-off-by: Daniel DeGrasse <daniel.degrasse@nxp.com>