MIPS: eXcite: Remove platform.

The platform has never been fully merged 

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Koeller <thomas.koeller@baslerweb.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mtd@lists.infradead.org
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: Wim Van Sebroeck <wim@iguana.be>