uki_addons: add 'fedora' SBAT suffix for UKI addons

JIRA: https://issues.redhat.com/browse/RHEL-93399

Upstream Status: RHEL-only

The SBAT suffix of distribution is missing Fedora in UKI addon. Without it, it will show '.rhel' in Fedora.

Signed-off-by: Li Tian <litian@redhat.com>

Author: litian1992

redhat/kernel.spec.template

@@ -2372,8 +2372,12 @@ BuildKernel() {
         # RHEL/CentOS specific .SBAT entries
 %if 0%{?centos}
         SBATsuffix="centos"
+%else
+%if 0%{?fedora}
+        SBATsuffix="fedora"
 %else
         SBATsuffix="rhel"
+%endif
 %endif
         SBAT=$(cat <<- EOF
 	linux,1,Red Hat,linux,$KernelVer,mailto:secalert@redhat.com