Commit ae8bf1a26e15 ("imx: add imx8m support") configured the
drm-imx-ldb kmod for imx_cortexa9 and imx_cortexa7 however it is only
applicable to imx_cortexa9 (imx6).
Fix this so that we can avoid a missing module config for cortexa7 when
moving to the 6.6 kernel.
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
eebe2d1a83