Removed trailing spaces in the most relevant files

Command used for the job:
egrep -rl ' $' --include *.c --include *.h --include  *.s --include  *.inc --include  *.txt *  | xargs sed -i 's/\s\+$//g'

Credits to Grant Murphy from Stack Overflow.

src/data/region_map/city_map_entries.h

@@ -1,4 +1,4 @@
-static const struct CityMapEntry sPokenavCityMaps[NUM_CITY_MAPS] = 
+static const struct CityMapEntry sPokenavCityMaps[NUM_CITY_MAPS] =
 {
     {
         .mapSecId = MAPSEC_LITTLEROOT_TOWN,