OMAP3: igep00x0: Enable required clocks for GPIO that are used.

Enable required clocks for GPIO to fix a boot issue introduced by commit
f33b9bd398 (arm: omap3: Enable clocks for
peripherals only if they are used).

Without this patch the u-boot freezes after the following messages

  OMAP36XX/37XX-GP ES1.2, CPU-OPP2, L3-200MHz, Max CPU Clock 1 Ghz
  IGEPv2 + LPDDR/NAND
  I2C:   ready
  DRAM:  512 MiB
  NAND:  512 MiB
  MMC:   OMAP SD/MMC: 0

Diving into the issue, the sequence that produces the u-boot freezes is

  setup_net_chip
   |--> gpio_direction_out
         |--> _set_gpio_dataout
               |--> __raw_writel

To avoid this we just need enable the clocks for GPIOs that are used, but it
would be interesting implement a mechanism to protect these situations and
make sure that the clock is enabled when we request a GPIO.

Signed-off-by: Enric Balletbo i Serra <eballetbo@gmail.com>

include/configs/omap3_igep00x0.h

@@ -37,6 +37,11 @@
 #define CONFIG_SHOW_BOOT_PROGRESS
 #endif
 
+/* GPIO banks */
+#define CONFIG_OMAP3_GPIO_3		/* GPIO64 .. 95 is in GPIO bank 3 */
+#define CONFIG_OMAP3_GPIO_5		/* GPIO128..159 is in GPIO bank 5 */
+#define CONFIG_OMAP3_GPIO_6		/* GPIO160..191 is in GPIO bank 6 */
+
 /* USB */
 #define CONFIG_MUSB_UDC			1
 #define CONFIG_USB_OMAP3		1