Revert "bcm2708: Add spare IRQs, GPIOs for MFDs (e.g. STMPE610)"

This reverts commit ceafb987d68f7ec0cec446cc28b65865cf36a5d6.
bcm2708_gpio: make room for additional GPIO chips

ARCH_NR_GPIOS is set to 54, and all is used by the onboard gpio controller.
This makes no room for additional gpio controllers to be added.

ARCH_NR_GPIOS limits how many gpios that can be used on a platform.
From gpiolib.c:
static struct gpio_desc gpio_desc[ARCH_NR_GPIOS];

Lift this restraint by using the default value for ARCH_NR_GPIOS, which is 256,
and make a new macro for the on-chip number of gpios.

Originally from https://github.com/notro/rpi-build/blob/master/patches/master/03-make-room-for-gpio-chips.patch
gitmodules: Add fbtft as a submodule
input: ft6x06 - add new i2c driver

The ft6x06 is a multitouch-capable captouch driver.  This adds support for
this part as an i2c device.
config: Add adafruit_defconfig

This config contains all the modules used by Adafruit customers.