common: Move clock functions into a new file

These three clock functions don't use driver model and should be migrated.
In the meantime, create a new file to hold them.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/freescale/qemu-ppce500/qemu-ppce500.c b/board/freescale/qemu-ppce500/qemu-ppce500.c
index 381d40d..b9c7146 100644
--- a/board/freescale/qemu-ppce500/qemu-ppce500.c
+++ b/board/freescale/qemu-ppce500/qemu-ppce500.c
@@ -323,7 +323,7 @@
 	sys_info->freq_processor[0] = freq;
 }
 
-int get_clocks (void)
+int get_clocks(void)
 {
 	sys_info_t sys_info;
 
@@ -350,7 +350,7 @@
  * get_bus_freq
  * return system bus freq in Hz
  *********************************************/
-ulong get_bus_freq (ulong dummy)
+ulong get_bus_freq(ulong dummy)
 {
 	sys_info_t sys_info;
 	get_sys_info(&sys_info);