configure: Allow to build tools without pixman
If pixman is not installed, it is currently not possible to run:
.../configure --disable-system --enable-tools
Seems like there was a dependency from one of the required source
files to pixman in the past, but since commit
1ac0206b2ae1ffaeec56
("qemu-timer.c: Trim list of included headers"), this dependency
should be gone. Thus allow to compile the tools without pixman now.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-id:
20200723141123.14765-1-thuth@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>