src/include: Add space after comma

Fix the following error detected by checkpatch.pl:

ERROR: space required after that ',' (ctx:VxV)

TEST=Build and run on Galileo Gen2

Change-Id: I297bfc3d03dc95b471d3bb4b13803e81963841b5
Signed-off-by: Lee Leahy <Leroy.P.Leahy@intel.com>
Reviewed-on: https://review.coreboot.org/18647
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

src/include/console/vtxprintf.h

@@ -22,9 +22,9 @@
  * On LLVM we can still just include stdarg.h.
  */
 #ifdef __GNUC__
-#define va_start(v,l)		__builtin_va_start(v,l)
+#define va_start(v, l)		__builtin_va_start(v, l)
 #define va_end(v)		__builtin_va_end(v)
-#define va_arg(v,l)		__builtin_va_arg(v,l)
+#define va_arg(v, l)		__builtin_va_arg(v, l)
 typedef __builtin_va_list	va_list;
 #else
 #include <stdarg.h>