common/board_f.c: change the macro name and remove it for PPC platforms

For most PPC platforms, they will call the first get_clocks() in
init_sequence_f[] as they define CONFIG_PPC. CONFIG_SYS_FSL_CLK is
then defined to call the second get_clocks(), which should be
redundant for PPC.

Signed-off-by: Gong Qianyu <Qianyu.Gong@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/include/configs/mx51evk.h b/include/configs/mx51evk.h
index 35c9346..32cd58e 100644
--- a/include/configs/mx51evk.h
+++ b/include/configs/mx51evk.h
@@ -18,7 +18,7 @@
 #define CONFIG_DISPLAY_CPUINFO
 #define CONFIG_DISPLAY_BOARDINFO
 
-#define CONFIG_FSL_CLK
+#define CONFIG_SYS_FSL_CLK
 #define CONFIG_SYS_TEXT_BASE	0x97800000
 
 #include <asm/arch/imx-regs.h>