src/console: Sanitize headers and IS_ENABLED usage

Alphabetise headers and remove any #if CONFIG_ guards around them.
Use #if IS_ENABLED(CONFIG_FOO) over #if CONFIG_FOO where applicable.

Change-Id: I2a616bcfb8470a1fa21c9e26271e81cca835272a
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/6057
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>

src/console/vsprintf.c

@@ -19,8 +19,8 @@
  * MA 02110-1301 USA
  */
 
-#include <string.h>
 #include <console/vtxprintf.h>
+#include <string.h>
 #include <trace.h>
 
 struct vsnprintf_context