Move is_power_of_two to misc_utils

src/common/misc/misc_utils.h

@@ -47,6 +47,8 @@ BEGIN_C_LINKAGE
 	) + 1                                        \
 )
 
+#define wapp_is_power_of_two(NUM) ((NUM & (NUM - 1)) == 0)
+
 #ifdef WAPP_PLATFORM_CPP
 END_C_LINKAGE