kdump-steamos: Move configuration file out of /etc

This patch main goal is to "un-Debianize" the configuration file
for kdump-steamos - thanks Emil (@xexaxo) for the discussions; it
is with a bit of a heavy heart I do that, but let's comply with the
modern distros ;-)

We hereby put the config file in a more standard path: /usr/share.
Usually users could override that with /etc/ file, but not in this
case, or at least, not for now. Kdump/pstore is expected to work
quietly, with no users' interference. Advanced users might want to
play with the configs though; and those can just go ahead and edit
the /usr/share/kdump/kdump.conf - it's all documented in the README.

In the future we can improve that by having the override mechanism
with the /etc file, let's see if we have a demand for that.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>

kdump-collect.sh

@@ -11,7 +11,7 @@
 #  and get stuck in this minimal initramfs with no output for the user.
 #
 
-. /usr/lib/kdump/kdump.etc
+. /usr/lib/kdump/kdump.conf
 
 VMCORE="/proc/vmcore"
 KDUMP_TIMESTAMP=$(date -u +"%Y%m%d%H%M")