AVR32: Add clk and gpio infrastructure for mmci

Implement functions for configuring the mmci pins, as well as
functions for getting the clock rate of the mmci controller.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
diff --git a/include/asm-avr32/arch-at32ap7000/gpio.h b/include/asm-avr32/arch-at32ap7000/gpio.h
index ca966e1..8d9b092 100644
--- a/include/asm-avr32/arch-at32ap7000/gpio.h
+++ b/include/asm-avr32/arch-at32ap7000/gpio.h
@@ -207,6 +207,7 @@
 void gpio_enable_usart3(void);
 void gpio_enable_macb0(void);
 void gpio_enable_macb1(void);
+void gpio_enable_mmci(void);
 
 #endif /* __ASM_AVR32_ARCH_GPIO_H__ */