v4l2_codec2: Add VP8 profiles to C2Config::profile_t.

This CL adds VP8 profiles to the C2Config::profile_t enum. The VP8
profiles are a bit different from other profiles as they control
filtering, but having these profiles present makes it a bit easier to
write VP8-related code.

Bug: 155138142
Test: arc.VideoEncodeAccel.h264_192p_i420_vm
Change-Id: I2c9ce04b46434f84d9241416669cbbb7e37b63d1