Allow robotics cape to be included in gateware design with any name.

Support PWM and H bridge GPIO control for the Robotics cape.

Enable power to the camera module by default to simplify board testing.

- Optimize MSS GPIO_2 usage.
- GPIOS build option now uses GPIOs for all cape pins except I2C on
  P9_PIN19 and P9_PIN20 which are hard-wired to MSS I2C.
- Move user LEDs control to MSS GPIO_2.

All gateware components now use the "DEFAULT" directory for their
default configuration. Previously a mix of "DEFAULT" and "NONE" were
used depending on the gateware component.