package/mesa3d: add KMSRO support for vc4

package/mesa3d: add KMSRO support for vc4

kmsro allow to support KMS displays with the renderonly layer used to
attach a GPU [1].

Quote from mesa3d meson.build: "kmsro driver requires one or more
renderonly drivers (vc4, etnaviv, freedreno)". But only vc4 support is
available by using the (deprecated) autotools build system [2].

This will also be used by mesa to support KMSRO with the upcomming
Panfrost and Lima Gallium drivers.

[1] https://cgit.freedesktop.org/mesa/mesa/commit/?id=ed65aeec7810a7d98a19461ba933bd77268cb0f6
[2] https://cgit.freedesktop.org/mesa/mesa/tree/configure.ac?h=mesa-19.0.1#n2864

Signed-off-by: Romain Naour <romain.naour@smile.fr>
Cc: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>