no-car/cbmemc: Fix compilation

the part !CAR && PRE_RAM is obviously meant as dummies. Unfortunately
cbmemc_tx_byte has wrong number of arguments and hence causes compilation
failure.

Found out when compiling for vexpress-a9.

Change-Id: Ic84d142bac5c455c2371fbc9439c898de04a974e
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/4267
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

src/include/console/cbmem_console.h

@@ -26,7 +26,7 @@ void cbmemc_tx_byte(unsigned char data);
 #else
 #define cbmemc_init()
 #define cbmemc_reinit()
-#define cbmemc_tx_byte()
+#define cbmemc_tx_byte(x)
 #endif
 
 #endif