media: dt-bindings: media: cal: update binding to use syscon

Update Device Tree bindings for the CAL driver to use syscon to access
the phy config register instead of trying to map it directly.

Signed-off-by: Benoit Parrot <bparrot@ti.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>