Use /efi as EFI mount directory

src/idmslinux_installer/plugins/mount_filesystems.py

@@ -35,7 +35,7 @@ class MountFilesystems(Plugin):
         self.description = "Mount Filesystems"
 
         self._boot_dir = '/boot'
-        self._efi_dir = '/boot/efi'
+        self._efi_dir = '/efi'
 
         Plugin.__init__(self)