xlat: update V4L2_COLORSPACE_* constants

xlat: update V4L2_COLORSPACE_* constants

* xlat/v4l2_colorspaces.in: Add #value_indexed.
(V4L2_COLORSPACE_DEFAULT): New constant introduced by Linux commit
v4.2-rc1~107^2~184.
(V4L2_COLORSPACE_ADOBERGB): Rename to V4L2_COLORSPACE_OPRGB, per Linux
commit v4.20-rc1~69^2~122.
(V4L2_COLORSPACE_SMPTE170M, V4L2_COLORSPACE_SMPTE240M,
V4L2_COLORSPACE_REC709, V4L2_COLORSPACE_BT878,
V4L2_COLORSPACE_470_SYSTEM_M, V4L2_COLORSPACE_470_SYSTEM_BG,
V4L2_COLORSPACE_JPEG, V4L2_COLORSPACE_SRGB, V4L2_COLORSPACE_OPRGB,
V4L2_COLORSPACE_BT2020, V4L2_COLORSPACE_RAW, V4L2_COLORSPACE_DCI_P3):
Add fallback definitions.