media: dt-bindings: media: renesas,fcp: Document RZ/{G2L,V2L} FCPVD bindings

Document FCPVD found in RZ/G2L alike SoCs. FCPVD block is similar to
FCP for VSP found on R-Car SoC's . It has 3 clocks compared to 1
clock on fcpv. Introduce new compatibles renesas,r9a07g044-fcpvd
for RZ/G2{L,LC} and renesas,r9a07g054-fcpvd for RZ/V2L to handle this
difference.

The 3 clocks are shared between du, vspd and fcpvd. No driver changes
are required as generic compatible string "renesas,fcpv" will be used
as a fallback.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>