driver: brcm: add mdio driver

Change-Id: Id873670f68a4c584e3b7b586cab28565bb5a1c27
Signed-off-by: Bharat Gooty <bharat.gooty@broadcom.com>
diff --git a/plat/brcm/board/stingray/include/sr_def.h b/plat/brcm/board/stingray/include/sr_def.h
index be0dee1..277836e 100644
--- a/plat/brcm/board/stingray/include/sr_def.h
+++ b/plat/brcm/board/stingray/include/sr_def.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2020, Broadcom
+ * Copyright (c) 2016-2021, Broadcom
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -193,6 +193,11 @@
 #define PLAT_CHIP_REV_GET	(mmio_read_32(ICFG_CHIP_REVISION_ID))
 
 /*******************************************************************************
+ * CMIC MII (MDIO) related constant
+ ******************************************************************************/
+#define PLAT_CMIC_MIIM_BASE	0x68920000U
+
+/*******************************************************************************
  * Timers related constants
  ******************************************************************************/
 /* ChipcommonG_tim0_TIM_TIMER1Load 0x68930000 */