Currently the code that adds the CapsuleMax variable is under a
Kconfig named 'EFI_HAVE_CAPSULE_UPDATE. Git history only shows a
single occurrence of that. The IS_ENABLED should be checking for
EFI_HAVE_CAPSULE_SUPPORT
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>