grub2: generate grub2-efi-image at build time

To eliminate human factor for crafting and signin this image.

Extras:
 - remove several unneeded patches

Change-Id: I78419b911afd2c8ec2a915e7007917e6870b0a36
Signed-off-by: Alexey Makhalov <[email protected]>
Reviewed-on: http://photon-jenkins.eng.vmware.com:8082/19822
Tested-by: gerrit-photon <[email protected]>
Reviewed-by: Shreenidhi Shedi <[email protected]>

Author: Alexey Makhalov

SPECS/grub2/fedora.patches

@@ -9,6 +9,8 @@ When we set a password, we just want that to mean you can't /edit/ an entry.
 Resolves: rhbz#1030176
 
 Signed-off-by: Peter Jones <[email protected]>
+[AM: fix conflict]
+Signed-off-by: Alexey Makhalov <[email protected]>
 ---
  util/grub.d/10_linux.in | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)
@@ -25,4 +27,4 @@ index 4a499c53a6..cf8d118698 100644
 +CLASS="--class gnu-linux --class gnu --class os --unrestricted"
 
  if [ "x${GRUB_DISTRIBUTOR}" = "x" ] ; then
-   OS="$(sed 's, release .*$,,g' /etc/system-release)"
+   OS=GNU/Linux