Add syslinux back to build

Used for iso building

roles/netbootxyz/vars/debian.yml

@@ -15,4 +15,6 @@ netbootxyz_packages:
   - liblzma-dev
   - libslirp-dev
   - mtools
+  - syslinux
+  - syslinux-common
   - toilet

roles/netbootxyz/vars/redhat.yml

@@ -9,5 +9,6 @@ netbootxyz_packages:
   - libslirp-devel
   - minizip-devel
   - mtools
+  - syslinux
   - xz-devel
   - make

roles/netbootxyz/vars/ubuntu.yml

@@ -15,6 +15,8 @@ netbootxyz_packages:
   - liblzma-dev
   - libslirp-dev
   - mtools
+  - syslinux
+  - syslinux-common
   - toilet
 
 pipxe_packages: