WiringPi: Android: Redefine some function that's not supported.

- Some api are not supported or redefined by android libraries. So to
support them on the android, this patch redefined the apis. And, some
api are not allowed. So avoid including the package by the problem.

Change-Id: Icaf2716a82dd98fc3c4fc3c597d4e67f3df8d755

Android.bp

@@ -47,7 +47,6 @@ cc_library_shared {
         "wiringPi/mcp3422.c",
         "wiringPi/pcf8591.c",
         "wiringPi/softTone.c",
-        "wiringPi/wpiExtensions.c",
     ],
 
     vendor_available: true,

wiringPi/wiringPi.h

@@ -31,6 +31,11 @@
 
 /*----------------------------------------------------------------------------*/
 
+#ifdef __ANDROID__
+#define __bswap_16(x)	bswap_16(x)
+#define __bswap_32(x)	bswap_32(x)
+#endif
+
 #ifndef	TRUE
 #define	TRUE	(1==1)
 #define	FALSE	(!TRUE)