OMAP4: OMAPFB: Always set a x_decim and y_decim in overlays

When using the framebuffer API to setup overlay, there's
currently no way to pass a x_decim and y_decim value in
so set some safe non-zero defaults.  Otherwise, when
the overlay is enabled, zero values will cause divide
by zero error in dispc.

Change-Id: Id2cb4bc4cb6be7b57e3ab5fc28fffc57163faecb
Signed-off-by: Mike J. Chen <mjchen@google.com>
Signed-off-by: Ruslan Bilovol <ruslan.bilovol@ti.com>
OMAP4: OMAPFB: Set overlay zorder to 0 if omapfb API used

Since there's no ioctl to set zorder when modifying overlays
using SETUP_PLANE, it's more useful to userland code if
overlay is 0, so they don't have to use sysfs and first
figure out which overlay is being used by omapfb.

Change-Id: I1c2eeecb0b950439e40eec895d6b89c73df2fd7e
Signed-off-by: Mike J. Chen <mjchen@google.com>
Signed-off-by: Ruslan Bilovol <ruslan.bilovol@ti.com>
OMAPDSS: OMAPFB : Add support for default display scaling.

Currently it is assumed that frame buffer size
is same as default panel size. With this assumption
GFX pipeline is always presented to default display FBDev.
GFX pipeline cannot scale so we cannot have a frame
buffer which is not equal to panel size (LCD | HDMI).
Updated the current logic of omapfb to pick video pipelines
in case scaling is required for FB to be presented to default
panel.

To provide FB size option is provided via command line.
e.g
omapfb.fb_opt=0,720,1280,1,640,480
each element is [fb_ix,width,height]

Change-Id: I9e2d40bed34c5fbf2bac31668d210e0bc586bb40
Signed-off-by: Dandawate Saket <dsaket@ti.com>
Signed-off-by: Muralidhar Dixit <murali.dixit@ti.com>