Adding extlinux-bootloader to Host, rhbz#1510553

Signed-off-by: Petr Šabata <contyk@redhat.com>

host.yaml

@@ -9,9 +9,9 @@ data:
         module: [ MIT ]
     dependencies:
         buildrequires:
-            bootstrap: f27
+            bootstrap: master
         requires:
-            platform: f27
+            platform: master
     references:
         community: https://fedoraproject.org/wiki/Host_and_Platform
         documentation: https://github.com/fedora-modularity/hp
@@ -43,18 +43,16 @@ data:
                 rationale: >-
                     Autogenerated by Host & Platform tooling.
                 ref: c10269f57f040733b3702d35b9076ef247b9058a
-            # grub2-2.02-19.fc27
-            # Diverged from BPL to address blocker bugs
+            # grub2-2.02-15.fc28
             grub2:
                 rationale: >-
                     Autogenerated by Host & Platform tooling.
-                ref: 307d0195543a534bef98328ba37f64a86fbfb462
-            # kernel-4.13.10-300.fc27
-            # Diverged from BPL to address blocker bugs
+                ref: e576c737b27c01d9f68fc122a1833ac23cd56f28
+            # kernel-4.13.0-0.rc6.git4.1.fc28
             kernel:
                 rationale: >-
                     Autogenerated by Host & Platform tooling.
-                ref: 289b4a0a16861e03a8d269aeb4e81401ad3f7e4f
+                ref: e66a6eb47149b9dd7d8ff139742d8463ec54910f
             # kexec-tools-2.0.15-12.fc28
             kexec-tools:
                 rationale: >-
@@ -64,7 +62,7 @@ data:
             linux-firmware:
                 rationale: >-
                     Autogenerated by Host & Platform tooling.
-                ref: eed9f21b0dd2f0dd78d54b8e80d61abbc15fc07d
+                ref: 9aa2671a4f14ddf1713bca14f25a942435613be6
             # mactel-boot-0.9-16.fc27
             mactel-boot:
                 rationale: >-
@@ -76,7 +74,6 @@ data:
                     Autogenerated by Host & Platform tooling.
                 ref: f64caafdc8a3443d1daa7988295408b44afb0637
             # shim-signed-13-0.7
-            # Diverged from BPL to address blocker bugs
             shim-signed:
                 rationale: >-
                     Provides the signed aarch64 binaries; provides the
@@ -92,4 +89,4 @@ data:
             uboot-tools:
                 rationale: >-
                     Autogenerated by Host & Platform tooling.
-                ref: f5a26b4e68d6c175d3634efc02df7e4f5a7f43e5
+                ref: 3ef111bdbb02704f4e60322dfabd1e12dd4e409e