Fix out of source builds.
https://bugs.gentoo.org/show_bug.cgi?id=488716

Index: libdc1394-2.2.1/dc1394/juju/Makefile.am
===================================================================
--- libdc1394-2.2.1.orig/dc1394/juju/Makefile.am
+++ libdc1394-2.2.1/dc1394/juju/Makefile.am
@@ -7,7 +7,7 @@ noinst_LTLIBRARIES = libdc1394-juju.la
 pkgjujuinclude_HEADERS = 
 endif
 
-AM_CFLAGS = -I$(top_srcdir)/dc1394
+AM_CFLAGS = -I$(top_srcdir) -I$(top_srcdir)/dc1394
 libdc1394_juju_la_SOURCES =  \
 	control.c \
 	capture.c \
Index: libdc1394-2.2.1/dc1394/usb/Makefile.am
===================================================================
--- libdc1394-2.2.1.orig/dc1394/usb/Makefile.am
+++ libdc1394-2.2.1/dc1394/usb/Makefile.am
@@ -7,7 +7,7 @@ noinst_LTLIBRARIES = libdc1394-usb.la
 pkgusbinclude_HEADERS = 
 endif
 
-AM_CFLAGS = -I$(top_srcdir)/dc1394 $(LIBUSB_CFLAGS)
+AM_CFLAGS = -I$(top_srcdir) -I$(top_srcdir)/dc1394 $(LIBUSB_CFLAGS)
 libdc1394_usb_la_LIBADD = $(LIBUSB_LIBS)
 libdc1394_usb_la_SOURCES =  \
 	control.c \