removed os2 support & support for building SDL with watcom.

src/hidapi/libusb/hid.c

@@ -418,9 +418,6 @@ static int is_language_supported(libusb_device_handle *dev, uint16_t lang)
 /* This function returns a newly allocated wide string containing the USB
    device string numbered by the index. The returned string must be freed
    by using free(). */
-#if defined(__OS2__) /* don't use iconv on OS/2: no support for wchar_t. */
-#define NO_ICONV
-#endif
 static wchar_t *get_usb_string(libusb_device_handle *dev, uint8_t idx)
 {
 	char buf[512];