Current driver configures the line mode of the DEI clients
from the open function directly. Even if the newly created context
is not yet scheduled, it updates some of the VPDMA registers.
This causes a problem in multi instance use case where just opening
the m2m device second time causes the running job to stall. This
happens especially if the source buffers used are NV12.

While all other configuration is being written to context specific
shadow registers, only line mode configuration is happening directly.

As there is no shadow register for line mode configuration, it's better
to separate the config_mode setting and line_mode setting. Call the
new "set_line_modes" functions only when actually loading the mmrs.
This makes sure that no non-running job will write to the registers
directly.
Signed-off-by: Nikhil Devshatwar <nikhil.nd@ti.com>
Signed-off-by: Benoit Parrot <bparrot@ti.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>