pinctrl: Rename Broadcom Capri pinctrl driver

To be consistent with other Broadcom drivers, the Broadcom Capri pinctrl
driver and its related CONFIG option are renamed to bcm281xx.

Devicetree compatible string and binding documentation use
"brcm,bcm11351-pinctrl" to match the machine binding here:
Documentation/devicetree/bindings/arm/bcm/bcm11351.txt

This driver supports pinctrl on BCM11130, BCM11140, BCM11351, BCM28145
and BCM28155 SoCs.

Signed-off-by: Sherman Yin <syin@broadcom.com>
Reviewed-by: Matt Porter <mporter@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>