All planes were PAGE aligned (ie. 4096 bytes aligned). This
is not consistent with YUV422 format, which requires Y, U
and V planes glued together.  The new implementation forces
the alignement on 8 bytes (DMA requirement), which is almost
always the case (granted by width x height being a multiple
of 8).

The test cases include tests in both YUV422 and RGB565 :
 - a picture of size 111 x 111 (cross RAM pages example)
 - a picture of size 1023 x 4 in (under 1 RAM page)
 - a picture of size 1024 x 4 in (exactly 1 RAM page)
 - a picture of size 1025 x 4 in (over 1 RAM page)
 - a picture of size 1280 x 1024 (many RAM pages)
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>