Inject multimedia package specific to rcar platform

Inject multimedia package specific to rcar platform

The packagegroup agl-graphical-multimedia needs to be extended
to pull in the BSP specific packagegroups.

Bug-AGL: SPEC-4029
Signed-off-by: Jan-Simon Möller <jsmoeller@linuxfoundation.org>
Change-Id: Ieed3263884304a7d00d9f468583f3db9370e3741
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl/+/26634
Tested-by: Jenkins Job builder account
ci-image-build: Jenkins Job builder account
ci-image-boot-test: Jenkins Job builder account
Reviewed-by: Harunobu Kurokawa <harunobu.kurokawa.dn@renesas.com>
(cherry picked from commit ae07296dfa03edd1eb25e0a632960bf71956c738)
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl/+/26592
Reviewed-by: Scott Murray <scott.murray@konsulko.com>