Switch to mkisofs for openSUSE distributions

In Tumbleweed genisoimage was dropped in favor of cdrtools,
so installing that no longer works. We can however install
mkisofs directly and switch to that as that is also available
in Leap 42.3 and Leap 15.0+ family distros.

Also drop dependency on libmysqlclient-devel which appears
unnecessary (and is no longer available with mariadb 10.2+)

Change-Id: Ie8402204b6cdf94c21865caba116d3fd1298c5ad
diff --git a/files/rpms-suse/nova b/files/rpms-suse/nova
index ae115d2..4103a40 100644
--- a/files/rpms-suse/nova
+++ b/files/rpms-suse/nova
@@ -4,7 +4,6 @@
 dnsmasq-utils # dist:opensuse-12.3,opensuse-13.1
 ebtables
 gawk
-genisoimage # required for config_drive
 iptables
 iputils
 kpartx
@@ -12,6 +11,7 @@
 libvirt # NOPRIME
 libvirt-python # NOPRIME
 mariadb # NOPRIME
+mkisofs # required for config_drive
 parted
 polkit
 # qemu as fallback if kvm cannot be used