ENGR00269245 MX6SL HDMI: print error message when HDMI cable plugin

ENGR00269245 MX6SL HDMI: print error message when HDMI cable plugin

When HDMI cable plugin, the frame buffer driver will print error
message "can't do pan display when fb is blank", it is cause by
sii902x driver call fb_set_var after fb power down.

sii902x driver should not mangement fb blank state, it should only
care its own power state.
Remove fb_blank function and replace it
with sii902x power management function.

Signed-off-by: Sandor Yu <R01008@freescale.com>