debug/gdb: always enable expat for the cross-gdb

There's no point in not supporting XML in the cross-gdb.
I mean, come on... ;-)

It's still the responsibility of the user to have the necessary
devel expat packages installed for his/her distro.

Reported-by: Trevor Woerner <twoerner@gmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

# Alpha specific configuration file

## select ARCH_SUPPORTS_32

## select ARCH_DEFAULT_32

## select ARCH_USE_MMU

## select ARCH_SUPPORTS_WITH_CPU

## select ARCH_SUPPORTS_WITH_TUNE

##

## help The Alpha architecture.