glib: version bump 2.42.0 -> 2.42.1

Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
gtk2: Disable rebuilds of pregenerated files

As we don't want to use tools outside of ptxdist, we should avoid
regenerating generated files within the gtk sources. For example
gtk-update-icon-cache may fail with different non-compatible versions.

This patch disables generating those files. Instead we use the
pregenerated files for now.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
gtk2: Remove leftover GTK2CORE

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