Add the virtual codec driver that uses the Fast Walsh Hadamard Transform.

Keiichi Watanabe contributed the multiplanar support.
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Co-Developed-by: NKeiichi Watanabe <keiichiw@chromium.org>
Signed-off-by: NKeiichi Watanabe <keiichiw@chromium.org>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>