MIPS: Kconfig: Use correct form for 'depends on'

Remove the CONFIG_ prefix from "depends on" as it makes the selection
not possible.

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: LKML <linux-kernel@vger.kernel.org>