build-sys: add 'hmp' option

Add an option to enable/disable HMP support, default to true. The
following commits are going to make --disable-hmp gradually work.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-ID: <20260828-qemu-no-hmp-v5-49-9227de146347@redhat.com>
3 files changed