OMAP4: 4430SDP: Add panel support to board file

4430SDP has two Taal DSI panels, connected to DSI 1 and DSI 2 modules.
The panels use a common PWM backlight, which will be implemented later
when the PWM driver has been improved to support the backlight.

Until the PWM driver has been improved, the following hack added to
arch/arm/mach-omap2/board-4430sdp.c can be used to set the backlight to
max:

static int omap_4430sdp_hack_backlight(void)
{
       twl_i2c_write_u8(TWL_MODULE_PWM, 0x7f, LED_PWM2OFF);
       twl_i2c_write_u8(TWL_MODULE_PWM, 0x7f, LED_PWM2ON);
       twl_i2c_write_u8(TWL6030_MODULE_ID1, 0x30, TWL6030_TOGGLE3);
       return 0;
}
late_initcall(omap_4430sdp_hack_backlight);

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