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/librfu_stwi.c

@@ -40,7 +40,7 @@ void STWI_init_all(struct RfuIntrStruct *interruptStruct, IntrFunc *interrupt, b
     gSTWIStatus->error = 0;
     gSTWIStatus->recoveryCount = 0;
     gSTWIStatus->sending = 0;
-    REG_RCNT = 0x100; // TODO: mystery bit? 
+    REG_RCNT = 0x100; // TODO: mystery bit?
     REG_SIOCNT = SIO_INTR_ENABLE | SIO_32BIT_MODE | SIO_115200_BPS;
     STWI_init_Callback_M();
     STWI_init_Callback_S();
@@ -118,7 +118,7 @@ void STWI_init_Callback_S(void)
     STWI_set_Callback_S(NULL);
 }
 
-// The callback can take 2 or 3 arguments. 
+// The callback can take 2 or 3 arguments.
 void STWI_set_Callback_M(void *callbackM)
 {
     gSTWIStatus->callbackM = callbackM;
@@ -594,7 +594,7 @@ static s32 STWI_start_Command(void)
 {
     u16 imeTemp;
 
-    // equivalent to gSTWIStatus->txPacket->rfuPacket32.command, 
+    // equivalent to gSTWIStatus->txPacket->rfuPacket32.command,
     // but the cast here is required to avoid register issue
     *(u32 *)gSTWIStatus->txPacket->rfuPacket8.data = 0x99660000 | (gSTWIStatus->reqLength << 8) | gSTWIStatus->reqActiveCommand;
     REG_SIODATA32 = gSTWIStatus->txPacket->rfuPacket32.command;