gallium/util: Remove the EMBEDDED_DEVICE macro because nobody use it

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/7641

Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Acked-by: Jose Fonseca <jfonseca@vmware.com>
Acked-by: Roland Scheidegger <sroland@vmware.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19552>

src/util/u_debug.c

@@ -46,7 +46,7 @@ void
 _debug_vprintf(const char *format, va_list ap)
 {
    static char buf[4096] = {'\0'};
-#if DETECT_OS_WINDOWS || defined(EMBEDDED_DEVICE)
+#if DETECT_OS_WINDOWS
    /* We buffer until we find a newline. */
    size_t len = strlen(buf);
    int ret = vsnprintf(buf + len, sizeof(buf) - len, format, ap);