riscv: timer: Add support for an early timer

Added support for timer_early_get_count() and timer_early_get_rate()
This is mostly useful in tracing.

Signed-off-by: Pragnesh Patel <pragnesh.patel@sifive.com>
Reviewed-by: Rick Chen <rick@andestech.com>
diff --git a/include/configs/ax25-ae350.h b/include/configs/ax25-ae350.h
index b2606e7..bd9c371 100644
--- a/include/configs/ax25-ae350.h
+++ b/include/configs/ax25-ae350.h
@@ -17,6 +17,11 @@
 #endif
 #endif
 
+#define RISCV_MMODE_TIMERBASE           0xe6000000
+#define RISCV_MMODE_TIMER_FREQ          60000000
+
+#define RISCV_SMODE_TIMER_FREQ          60000000
+
 /*
  * CPU and Board Configuration Options
  */