FBDEV: cobalt_lcdfb: Drop SEAD3 support

FBDEV: cobalt_lcdfb: Drop SEAD3 support

The SEAD3 board no longer uses the cobalt_lcdfb driver, so remove the
SEAD3-specific code from it.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Acked-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Ondrej Zary <linux@rainbow-software.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Simon Horman <horms+renesas@verge.net.au>
Cc: linux-mips@linux-mips.org
Cc: linux-fbdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14060/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>