ARM: keystone2: Remove unsed external clocks

Remove unused external clocks and make a common definition
for all keystone platforms.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
diff --git a/board/ti/ks2_evm/board_k2e.c b/board/ti/ks2_evm/board_k2e.c
index e33cc64..dc00cf6 100644
--- a/board/ti/ks2_evm/board_k2e.c
+++ b/board/ti/ks2_evm/board_k2e.c
@@ -18,12 +18,7 @@
 	[sys_clk]	= 100000000,
 	[alt_core_clk]	= 100000000,
 	[pa_clk]	= 100000000,
-	[ddr3_clk]	= 100000000,
-	[mcm_clk]	= 312500000,
-	[pcie_clk]	= 100000000,
-	[sgmii_clk]	= 156250000,
-	[xgmii_clk]	= 156250000,
-	[usb_clk]	= 100000000,
+	[ddr3a_clk]	= 100000000,
 };
 
 static struct pll_init_data core_pll_config[NUM_SPDS] = {