MIPS: config: Remove left-over BACKLIGHT_LCD_SUPPORT

The CONFIG_BACKLIGHT_LCD_SUPPORT was removed in commit 8c5dc8d9
("video: backlight: Remove useless BACKLIGHT_LCD_SUPPORT kernel
symbol"). Options protected by CONFIG_BACKLIGHT_LCD_SUPPORT are now
available directly.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: James Hartley <james.hartley@sondrel.com>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org