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>

platform/kendryte/k210/platform.c

@@ -42,6 +42,7 @@ static struct aclint_mswi_data mswi = {
 };
 
 static struct aclint_mtimer_data mtimer = {
+	.mtime_freq = K210_ACLINT_MTIMER_FREQ,
 	.mtime_addr = K210_ACLINT_MTIMER_ADDR +
 		      ACLINT_DEFAULT_MTIME_OFFSET,
 	.mtime_size = ACLINT_DEFAULT_MTIME_SIZE,

platform/kendryte/k210/platform.h

@@ -14,7 +14,7 @@
 #define K210_HART_COUNT		2
 
 #define K210_UART_BAUDRATE	115200
-
+#define K210_ACLINT_MTIMER_FREQ	7800000
 #define K210_CLK0_FREQ		26000000UL
 #define K210_PLIC_NUM_SOURCES	65