drivers: net: cpsw: remove hard coding bd ram for cpsw

BD ram address may vary in various SOC, so removing the hardcoding and
passing the same information through platform data

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
diff --git a/board/ti/am335x/board.c b/board/ti/am335x/board.c
index 7138d73..15e249d 100644
--- a/board/ti/am335x/board.c
+++ b/board/ti/am335x/board.c
@@ -435,6 +435,7 @@
 	.ale_entries		= 1024,
 	.host_port_reg_ofs	= 0x108,
 	.hw_stats_reg_ofs	= 0x900,
+	.bd_ram_ofs		= 0x2000,
 	.mac_control		= (1 << 5),
 	.control		= cpsw_control,
 	.host_port_num		= 0,