MIPS: Loongson1B: use common clock infrastructure instead of private APIs

Use common clock infrastructure instead of private APIs.
1. Enable COMMON_CLK in the Kconfig.
2. Remove private clock APIs, which are replaced by the code in
   drivers/clk/clk-ls1x.c.
3. Modify header file for drivers/clk/clk-ls1x.c.

Signed-off-by: Kelvin Cheung <keguang.zhang@gmail.com>
Patchwork: http://patchwork.linux-mips.org/patch/4431
Signed-off-by: John Crispin <blogic@openwrt.org>
diff --git a/arch/mips/include/asm/mach-loongson1/regs-clk.h b/arch/mips/include/asm/mach-loongson1/regs-clk.h
index 8efa7fb..a81fa3d 100644
--- a/arch/mips/include/asm/mach-loongson1/regs-clk.h
+++ b/arch/mips/include/asm/mach-loongson1/regs-clk.h
@@ -20,14 +20,15 @@
 
 /* Clock PLL Divisor Register Bits */
 #define DIV_DC_EN			(0x1 << 31)
-#define DIV_DC				(0x1f << 26)
 #define DIV_CPU_EN			(0x1 << 25)
-#define DIV_CPU				(0x1f << 20)
 #define DIV_DDR_EN			(0x1 << 19)
-#define DIV_DDR				(0x1f << 14)
 
 #define DIV_DC_SHIFT			26
 #define DIV_CPU_SHIFT			20
 #define DIV_DDR_SHIFT			14
 
+#define DIV_DC_WIDTH			5
+#define DIV_CPU_WIDTH			5
+#define DIV_DDR_WIDTH			5
+
 #endif /* __ASM_MACH_LOONGSON1_REGS_CLK_H */