Move bswap.h to include/qemu/bswap.h

Before integrating upstream patches, we need to move source
files around to match the new directory structure used there.
This is the first of such changes.

Change-Id: Ib42669003851aa5a5295dd66cfebb307c63f054f
diff --git a/Makefile.android b/Makefile.android
index 2e7ac74..73013e3 100644
--- a/Makefile.android
+++ b/Makefile.android
@@ -151,6 +151,8 @@
 # Needed to build fpu/softfloat-native.h properly
 MY_CFLAGS += -D_GNU_SOURCE=1
 
+MY_CFLAGS += -I$(LOCAL_PATH)/include
+
 # A useful function that can be used to start the declaration of a host
 # module. Avoids repeating the same stuff again and again.
 # Usage: