OMAPFB: remove unused FB_OMAP_BOOTLOADER_INIT config option

code depending on FB_OMAP_BOOTLOADER_INIT has been removed long before
(e.g. Tomi Valkeinen, 03 Mar 2011: OMAP: DSS2: Remove FB_OMAP_BOOTLOADER_INIT
support), but the option still exists Kconfig and has no use

Signed-off-by: Peter Meerwald <p.meerwald@bct-electronic.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>