ENGR00154108-3 mxc ldb: make ldb support two ipu in separate mode

ENGR00154108-3 mxc ldb: make ldb support two ipu in separate mode

make ldb support two ipu in separate mode

cmdline option changed:

 "ldb=spl0/1"       --      split mode on DI0/1
 "ldb=dul0/1"       --      dual mode on DI0/1
 "ldb=sin0/1"       --      single mode on LVDS0/1
 "ldb=sep0/1" 	 --      separate mode begin from LVDS0/1

 there are two LVDS channels(LVDS0 and LVDS1) which can transfer video
 datas, there two channels can be used as split/dual/single/separate mode.

 split mode means display data from DI0 or DI1 will send to both channels
 LVDS0+LVDS1.
 dual mode means display data from DI0 or DI1 will be duplicated on LVDS0
 and LVDS1, it said, LVDS0 and LVDS1 has the same content.
 single mode means only work for DI0/DI1->LVDS0 or DI0/DI1->LVDS1.
 separate mode means you can make DI0/DI1->LVDS0 and DI0/DI1->LVDS1 work
 at the same time.

Signed-off-by: Jason Chen <b02280@freescale.com>