media: dt-bindings: media: Correct samsung-fimc parallel port numbering

The parallel port nodes should be numbered 1 and 2, not 0 and 1
for A and B respectively.  The driver has always implemented 1
and 2 and the in-tree Goni DTS uses 1 as port A as well.  Update
the documentation to match this behaviour.

Signed-off-by: Jonathan Bakker <xc-racer2@live.ca>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.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>