lib: sbi: Add timer frequency to struct sbi_timer_device

Generic mdelay() and udelay() functions can be provided by the
sbi_timer framework if timer frequency is available in the timer
instance provided by the platform support or timer driver.

This patch adds timer frequency (timer_freq) member in the
struct sbi_timer_device for above purpose.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Xiang W <wxjstz@126.com>

include/sbi/sbi_timer.h

@@ -17,6 +17,9 @@ struct sbi_timer_device {
 	/** Name of the timer operations */
 	char name[32];
 
+	/** Frequency of timer in HZ */
+	unsigned long timer_freq;
+
 	/** Get free-running timer value */
 	u64 (*timer_value)(void);