Bug#1031424: add config option to control mixed-mode EFI on x86

Package: debian-cd
Version: 3.1.36
Severity: normal

[ Reminder for me ]

I've added support for mixed-mode EFI stuff on amd64 builds. Add an
option to enable/disable it, so that local hack builds don't need both
amd64 and i386 d-i builds to function.

-- System Information:
Debian Release: 11.6
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable'), (500, 'oldstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.10.0-21-amd64 (SMP w/8 CPU threads)
Kernel taint flags: TAINT_WARN, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages debian-cd depends on:
ii  apt                        2.2.4
ii  bc                         1.07.1-2+b2
ii  bzip2                      1.0.8-4
ii  cpp                        4:10.2.1-1
ii  curl                       7.74.0-1.3+deb11u5
ii  dctrl-tools [grep-dctrl]   2.24-3+b1
ii  dpkg-dev                   1.20.12
ii  genisoimage                9:1.1.11-3.2
pn  libcompress-zlib-perl      <none>
pn  libdigest-md5-perl         <none>
ii  libdigest-sha-perl         6.02-1+b3
ii  libdpkg-perl               1.20.12
ii  libfile-slurp-perl         9999.32-1
ii  libyaml-libyaml-perl       0.82+repack-1+b1
ii  lynx                       2.9.0dev.6-3~deb11u1
ii  make                       4.3-4.1
ii  perl [libdigest-sha-perl]  5.32.1-4+deb11u2
ii  tofrodos                   1.7.13+ds-5
ii  wget                       1.21-1+deb11u1
ii  xorriso                    1.5.2-1

Versions of packages debian-cd recommends:
ii  dosfstools       4.2-1
ii  hfsutils         3.2.6-15
ii  isolinux         3:6.04~git20190206.bf6db5b4+dfsg1-3
ii  mtools           4.0.26-1
ii  syslinux-common  3:6.04~git20190206.bf6db5b4+dfsg1-3

debian-cd suggests no packages.

-- no debconf information