time: move timer APIs to include/time.h

The include/common.h is a collection of unrelated declarations,
macros, etc.

It is horrible to include such a cluttered header just for some
timer functions.  Split out timer functions into include/time.h.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

include/common.h

@@ -20,6 +20,7 @@ typedef volatile unsigned char	vu_char;
 
 #include <config.h>
 #include <errno.h>
+#include <time.h>
 #include <asm-offsets.h>
 #include <linux/bitops.h>
 #include <linux/delay.h>
@@ -580,12 +581,6 @@ void ddr_enable_ecc(unsigned int dram_size);
 #endif
 #endif
 
-/*
- * Return the current value of a monotonically increasing microsecond timer.
- * Granularity may be larger than 1us if hardware does not support this.
- */
-ulong timer_get_us(void);
-
 /* $(CPU)/cpu.c */
 static inline int cpumask_next(int cpu, unsigned int mask)
 {
@@ -724,7 +719,6 @@ void	external_interrupt (struct pt_regs *);
 void	irq_install_handler(int, interrupt_handler_t *, void *);
 void	irq_free_handler   (int);
 void	reset_timer	   (void);
-ulong	get_timer	   (ulong base);
 
 /* Return value of monotonic microsecond timer */
 unsigned long timer_get_us(void);

include/time.h

@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _TIME_H
+#define _TIME_H
+
+unsigned long get_timer(unsigned long base);
+
+/*
+ * Return the current value of a monotonically increasing microsecond timer.
+ * Granularity may be larger than 1us if hardware does not support this.
+ */
+unsigned long timer_get_us(void);
+
+#endif /* _TIME_H */