Added soon-to-be-requisite missing include.

src/drivers/bus/eisa.c

 #include "io.h"
 #include "timer.h"
 #include "console.h"
+#include "dev.h"
 #include "eisa.h"
 
 /*

src/drivers/bus/isa.c

 #include "string.h"
 #include "console.h"
 #include "config/isa.h"
+#include "dev.h"
 #include "isa.h"
 
 /*

src/drivers/bus/isapnp.c

 #include "timer.h"
 #include "io.h"
 #include "console.h"
+#include "dev.h"
 #include "isapnp.h"
 
 /**

src/drivers/bus/mca.c

 #include "string.h"
 #include "io.h"
 #include "console.h"
+#include "dev.h"
 #include "mca.h"
 
 /*

src/interface/pxe/pxe.c

  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "dev.h"
 #include "pxe.h"
 
 /* Global pointer to currently installed PXE stack */