OMAP1: pass LCD config with omapfb_set_lcd_config()

LCD config for old omapfb driver is passed with OMAP_TAG_LCD from board
files or from the bootloader. In an effort to remove OMAP_TAG_LCD, this
patch adds omapfb_set_lcd_config() function that the board files can
call to set the LCD config.

This has the drawback that configuration can no longer come from the
bootloader. Of the boards supported by the kernel, this should only
affect N770 which depends on the data from the bootloader. This patch
adds an LCD config for N770 to its board files, but that is most
probably broken. Fixing this would need information about the HW setup
in N770 boards.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>