Pass iPXE interface to Fedora/RHEL installers

src/fedora.ipxe

@@ -54,7 +54,7 @@ goto boot
 
 :boot
 imgfree
-kernel http://${fedora_mirror}/${dir}/images/pxeboot/vmlinuz repo=http://${fedora_mirror}/${dir} ${params} ${console} initrd=initrd.img
+kernel http://${fedora_mirror}/${dir}/images/pxeboot/vmlinuz repo=http://${fedora_mirror}/${dir} ${params} ${console} BOOTIF=${netX/mac} ip=dhcp initrd=initrd.img
 initrd http://${fedora_mirror}/${dir}/images/pxeboot/initrd.img
 echo
 echo MD5sums:

src/rhel.ipxe

@@ -40,7 +40,7 @@ isset ${rhel_base_url} && goto boot || echo URL not set... && goto url_set
 
 :boot
 imgfree
-kernel ${rhel_base_url}/os/${rhel_arch}/images/pxeboot/vmlinuz repo=${rhel_base_url}/os/${rhel_arch} ${console} initrd=initrd.img
+kernel ${rhel_base_url}/os/${rhel_arch}/images/pxeboot/vmlinuz repo=${rhel_base_url}/os/${rhel_arch} ${console} BOOTIF=${netX/mac} ip=dhcp initrd=initrd.img
 initrd ${rhel_base_url}/os/${rhel_arch}/images/pxeboot/initrd.img
 md5sum vmlinuz initrd.img
 boot