cairo: Missing dependency XORG_LIB_XEXT

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
xorg-lib-Xi: Missing dependency LIB_XFIXES

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
systemd: version bump 216 -> 217

Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
libltdl: Version bump 1.5 -> 2.4.3

To get this compiling without a help2man dependency, we have to use a
NOOP binary for help2man instead.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
libxml2: update to 2.9.2

Also integrated two changes from upstream fixing two minor issues.
Build successfully tested against all ptxdist packages requiring
libxml2, no runtime tests.