Preprocessor related fix-ups.

- olimex.c, rf2500.c, uif.c:
    add missing includes for malloc(), free() and atoi().
  - uif.c: define serial port speeds based on need, not platform.
  - uif.c: if !__linux__, stub open_olimex_iso() is not needed.

olimex.c

@@ -18,6 +18,7 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <usb.h>
 

rf2500.c

@@ -17,6 +17,7 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <usb.h>
 

uif.c

@@ -36,8 +36,10 @@
 #include "util.h"
 #include "output.h"
 
-#if defined(__APPLE__) || defined(__OpenBSD__)
+#ifndef B460800
 #define B460800 460800
+#endif
+#ifndef B500000
 #define B500000 500000
 #endif
 
@@ -116,13 +118,6 @@ static int open_olimex_iso(const char *device)
 
         return fd;
 }
-#else
-static int open_olimex_iso(const char *device)
-{
-	printc_err("open_olimex_iso: this driver is only supported on "
-		   "Linux\n");
-	return -1;
-}
 #endif
 
 transport_t uif_open(const char *device, uif_type_t type)

usbutil.c

@@ -17,6 +17,7 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include "usbutil.h"
 #include "util.h"