[media] media: rcar-vin: make V4L2_FIELD_INTERLACED standard dependent

The field V4L2_FIELD_INTERLACED is standard dependent and should not
unconditionally be equivalent to V4L2_FIELD_INTERLACED_TB.

This patch adds a check to see if the video standard can be obtained and
if it's a 60 Hz format. If the condition is met V4L2_FIELD_INTERLACED
is treated as V4L2_FIELD_INTERLACED_BT if not as
V4L2_FIELD_INTERLACED_TB.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>