src/*: Remove the last remnants of struct keyboard

Change-Id: I7d0e8d2119a470428cfc01c0738b8988ab75ba2d
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/5624
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

src/include/pc80/keyboard.h

@@ -1,10 +1,6 @@
 #ifndef PC80_KEYBOARD_H
 #define PC80_KEYBOARD_H
 
-struct pc_keyboard {
-	/* No initialization parameters for now */
-};
-
 void pc_keyboard_init(void);
 void set_kbc_ps2_mode(void);