[mucurses] Add missing FILE_LICENCE declarations

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/hci/mucurses/alert.c

  *
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 /**
  * Audible signal
  *

src/hci/mucurses/edging.c

  *
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 /**
  * Draw borders from single-byte characters and renditions around a
  * window

src/hci/mucurses/kb.c

  * MuCurses keyboard input handling functions
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #define INPUT_DELAY 		200 // half-blocking delay timer resolution (ms)
 #define INPUT_DELAY_TIMEOUT 	1000 // half-blocking delay timeout
 

src/hci/mucurses/print_nadv.c

  *
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 /**
  * Add string of single-byte characters and renditions to a window
  *

src/hci/mucurses/slk.c

  * Soft label key functions
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 #define MIN_SPACE_SIZE 2
 
 #define SLK_MAX_LABEL_LEN 8

src/hci/mucurses/windows.c

  *
  */
 
+FILE_LICENCE ( GPL2_OR_LATER );
+
 /**
  * Delete a window
  *