samples: display: update rtk7eka6m3b00001bu shield related samples

The rtk7eka6m3b00001bu need addtional ek_ra8d1_rtk7eka6m3b00001bu shield
to build with ek_ra8d1/r7fa8d1bhecbd platform. This commit to update
extra args to select it when build with twister

Signed-off-by: The Nguyen <the.nguyen.yf@renesas.com>