lib/datetime: Specify license in emu module

Other platforms specify license in platform-specific files but corresponding
code for emu is in kernel, so datetime ends up without license section.

Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

grub-core/lib/datetime.c

@@ -21,6 +21,11 @@
 #include <grub/i18n.h>
 #include <grub/misc.h>
 #include <grub/mm.h>
+#ifdef GRUB_MACHINE_EMU
+#include <grub/dl.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+#endif
 
 static const char *const grub_weekday_names[] =
 {