configs: enable efidebug and EFI http boot on QEMU aarch64

EFI HTTP is a useful option to have by default and is working reliably on
QEMU. Let's enable it by default, since we have no size limitations.
While at it enable 'efidebug' as well, which is currently needed to
configure the EFI HTTP boot options.

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>