drm: ingenic-drm: add MODULE_DEVICE_TABLE

so that the driver can load by matching the device tree
if compiled as module.

Cc: stable@vger.kernel.org # v5.3+
Fixes: 90b86fcc

 ("DRM: Add KMS driver for the Ingenic JZ47xx SoCs")
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://patchwork.freedesktop.org/patch/msgid/1694a29b7a3449b6b662cec33d1b33f2ee0b174a.1588574111.git.hns@goldelico.com