unicore32 machine related: add frame buffer driver for pkunity-v3 soc

change from original version -- by advice of Paul Mundt
1. remove videomemorysize definitions
2. remove unifb_enable and unifb_setup
3. use dev_warn instead of printk in fb driver
4. remove judgement for FB_ACCEL_PUV3_UNIGFX
5. adjust clk_get and clk_set_rate calls
6. add resources definitions
7. remove unifb_option
8. adjust register for platform_device
9. adjust unifb_ops position and unifb_regs assignment position

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Arnd Bergmann <arnd@arndb.de>

include/linux/fb.h

@@ -152,6 +152,8 @@
 #define FB_ACCEL_PROSAVAGE_DDR  0x8d	/* S3 ProSavage DDR             */
 #define FB_ACCEL_PROSAVAGE_DDRK 0x8e	/* S3 ProSavage DDR-K           */
 
+#define FB_ACCEL_PUV3_UNIGFX	0xa0	/* PKUnity-v3 Unigfx		*/
+
 struct fb_fix_screeninfo {
 	char id[16];			/* identification string eg "TT Builtin" */
 	unsigned long smem_start;	/* Start of frame buffer mem */