media: dt-bindings: media: camss: Fixup vdda regulator descriptions sdm845

If we review the schematic for RB3 Thundercomm document Turbox-845 we see
that the CAMSS CSI PHY has the same basic power-rail layout as UFS, PCIe
and USB PHYs.

We should therefore have two regulator declarations as is the case for UFS,
PCIe and USB.

Reviewed-by: Robert Foss <robert.foss@linaro.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
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>