[media] sh_veu: fix the buffer size calculation

The 'bytesperline' value only indicates the stride of the Y plane
if the color format is planar, such as NV12. When calculating
the total plane size, the size of CbCr plane must also be considered.

Signed-off-by: Katsuya Matsubara <matsu@igel.co.jp>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>