ARM i.MX35: build in pinctrl support.

shawn.guo: While at it, we drop 'select PINCTRL' from SOC_IMX35, since
it's been covered by ARCH_MXC.

Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: devicetree@vger.kernel.org
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Eric Bénard <eric@eukrea.com>
Signed-off-by: Denis Carikli <denis@eukrea.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>