Add AVR32 LCD support

This patch adds support for the AVR32 LCD controller.  This patch is
based off the latest u-boot-video.

A quick summary of what's going on:-

Enable LCDC pixel clock
Enable LCDC port pins
Add framebuffer pointer to global_data struct
Allocate framebuffer

To use the new code, update your board config to include something like
this:-

#define CONFIG_LCD			1

#if defined(CONFIG_LCD)
#define CONFIG_CMD_BMP
#define CONFIG_ATMEL_LCD		1
#define LCD_BPP				LCD_COLOR16
#define CONFIG_BMP_16BPP		1
#define CONFIG_FB_ADDR			0x10600000
#define CONFIG_WHITE_ON_BLACK		1
#define CONFIG_VIDEO_BMP_GZIP 		1
#define CONFIG_SYS_VIDEO_LOGO_MAX_SIZE		262144
#define CONFIG_ATMEL_LCD_BGR555		1
#define CONFIG_SYS_CONSOLE_IS_IN_ENV	1
#define CONFIG_SPLASH_SCREEN		1
#endif

The standard U-Boot BMP and Splash-screen features should just work.

Signed-off-by: Mark Jackson <mpfj@mimc.co.uk>
[agust@denx.de: fixed some style issues]
Signed-off-by: Anatolij Gustschin <agust@denx.de>
diff --git a/cpu/at32ap/at32ap700x/clk.c b/cpu/at32ap/at32ap700x/clk.c
index 2c2e19c..742bc6b 100644
--- a/cpu/at32ap/at32ap700x/clk.c
+++ b/cpu/at32ap/at32ap700x/clk.c
@@ -65,6 +65,11 @@
 #ifdef CONFIG_PLL
 	/* Use PLL0 as main clock */
 	sm_writel(PM_MCCTRL, SM_BIT(PLLSEL));
+
+#ifdef CONFIG_LCD
+	/* Set up pixel clock for the LCDC */
+	sm_writel(PM_GCCTRL(7), SM_BIT(PLLSEL) | SM_BIT(CEN));
+#endif
 #endif
 }