drm/vc4: dsi: Introduce a variant structure

stable inclusion
from stable-v5.10.137
commit 6cc1edddcf02f69664887ea7ed4b604481ae300e
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6cc1edddcf02f69664887ea7ed4b604481ae300e



--------------------------------

[ Upstream commit d1d195ce ]

Most of the differences between DSI0 and DSI1 are handled through the
ID. However, the BCM2711 DSI is going to introduce one more variable to
the mix and will break some expectations of the earlier, simpler, test.

Let's add a variant structure that will address most of the differences
between those three controllers.

Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20201203132543.861591-5-maxime@cerno.tech


Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>