[bootloader] Allow skipping the EFI fallback

src/modules/bootloader/bootloader.conf

@@ -33,3 +33,11 @@ grubCfg: "/boot/grub/grub.cfg"
 # names since no sanitizing is done.
 #
 # efiBootloaderId: "dirname"
+
+# Optionally install a copy of the GRUB EFI bootloader as the EFI
+# fallback loader (either bootia32.efi or bootx64.efi depending on
+# the system). This may be needed on certain systems (Intel DH87MC
+# seems to be the only one). If you set this to false, take care
+# to add another module to optionally install the fallback on those
+# boards that need it.
+installEFIFallback: true

src/modules/bootloader/main.py

@@ -269,6 +269,7 @@ def install_grub(efi_directory, fw_type):
             os.makedirs(install_efi_boot_directory)
 
         # Workaround for some UEFI firmwares
+        if libcalamares.job.configuration.get("installEFIFallback", True):
             efi_file_source = os.path.join(install_efi_directory_firmware,
                                         efi_bootloader_id,
                                         efi_grub_file)