Add kernel post-installation script to regenerate grub2 config

Since we now allow using Fedora kernel, add a script to generate proper
bootloader configuration then. Standard Fedora mechanism relies on
Boot Loader Specification support in grub2, which sadly does not support
Xen, so it is useless in Qubes.

(cherry picked from commit 2a14ae9c0b)

Conflicts:
	rpm_spec/core-dom0-linux.spec

rpm_spec/core-dom0-linux.spec

@@ -144,6 +144,7 @@ install -d $RPM_BUILD_ROOT/etc/udev/rules.d
 install -m 644 system-config/00-qubes-ignore-devices.rules $RPM_BUILD_ROOT/etc/udev/rules.d/
 install -m 644 system-config/60-persistent-storage.rules $RPM_BUILD_ROOT/etc/udev/rules.d/
 install -m 644 -D system-config/disable-lesspipe $RPM_BUILD_ROOT/etc/profile.d/zz-disable-lesspipe
+install -m 755 -D system-config/kernel-grub2.install $RPM_BUILD_ROOT/usr/lib/kernel/install.d/90-grub2.install
 
 ### Icons
 mkdir -p $RPM_BUILD_ROOT/usr/share/qubes/icons
@@ -255,6 +256,7 @@ chmod -x /etc/grub.d/10_linux
 # Others
 /etc/sysconfig/iptables
 /etc/sysconfig/ip6tables
+/usr/lib/kernel/install.d/90-grub2.install
 /etc/sysconfig/modules/qubes-dom0.modules
 /etc/sysconfig/modules/cpufreq-xen.modules
 /etc/sudoers.d/qubes

system-config/kernel-grub2.install

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+grub2-mkconfig -o /boot/grub2/grub.cfg