A Xen guest without emulated graphics has two ways to be given a display,
and the kernel drivers for them are unrelated: xen-fbfront speaks the vfb
protocol through legacy fbdev, while xen_drm_front speaks displif on a
vdispl xenbus device. Only the second has a DRM driver, and nothing in
the tree packaged it.
Package it for the three targets whose kernels have Xen guest support. It
needs xen-front-pgdir-shbuf, a hidden tristate with no package of its
own, so both modules ship together.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>