[arm64] Enable I2C_HID_OF_ELAN as module

Several platforms including some MT8186 Chromebooks, SC7280 Chromebooks, and the SC8280XP Thinkpad X13s use an ELAN touchscreen. The Thinkpad used to use the i2c-hid-of driver for this but the upstream has later switched to the ELAN-specific driver. Enable it as a module.

It depends on drm through the recent panel-follower changes, so move it to the fb-modules udeb.