include/device/dram: Fix DDR3-1866

The PLL multiplier value is off by one for DDR3-1866 due to a
wrong TCK value, resulting in DDR3-1600 being used by the PLL.

Needs test on real hardware !

Change-Id: I657b813889945f0d9990dd11680a3d3a25b53467
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/13613
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/include/device/dram/ddr3.h

@@ -36,7 +36,7 @@
 #define TCK_1333MHZ     192
 #define TCK_1200MHZ     212
 #define TCK_1066MHZ     240
-#define TCK_933MHZ      275
+#define TCK_933MHZ      274
 #define TCK_800MHZ      320
 #define TCK_666MHZ      384
 #define TCK_533MHZ      480