usb: phy: fsm: don't depend on indirect includes

this header uses spinlocks and errno values, so
we must include <linux/spinlock.h> and <linux/errno.h>
to avoid build errors.
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/phy/phy-fsm-usb.h

@@ -15,6 +15,9 @@
  * 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+
 #undef VERBOSE
 
 #ifdef VERBOSE