t2080rdb/rcw: update ddr frequency from 1600MT/s to 1867MT/s

T2080RDB RevC uses new SODIMM 1867MT/s instead of previous 1600MT/s.
So update RCW to support new DDR frequency 1867MT/s by default.
Reserve the old 1600MT/s in comment for users in needed.

Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>

board/freescale/t208xrdb/t2080_rcw.cfg

@@ -10,7 +10,10 @@ aa55aa55 010e0100
 
 #For T2080 v1.1
 #SerDes=0x66_0x15, Core:1800MHz, DDR:1600MT/s
-1206001b 15000000 00000000 00000000
+#1206001b 15000000 00000000 00000000
+
+#SerDes=0x66_0x15, Core:1800MHz, DDR:1867MT/s
+1207001b 15000000 00000000 00000000
 66150002 00000000 e8104000 c1000000
 00800000 00000000 00000000 000307fc
 00000000 00000000 00000000 00000004