Merge pull request contiki-os#1867 from MohamedSeliem/patch-6

update uart1.c to include Special function registers bits definitions

Author: g-oikonomou

cpu/cc253x/dev/uart1.c

@@ -12,6 +12,7 @@
 #include <string.h>
 
 #include "cc253x.h"
+#include "sfr-bits.h"
 #include "dev/uart1.h"
 
 #if UART1_ENABLE