The vga reset handler overwrites some cirrus registers, causing reboots
to corrupt cirrus state to the point that guests can only bring up 640x480
resolutions.

Fix by adding a dedicated cirrus reset handler (which calls the common vga
handler).
Signed-off-by: NAvi Kivity <avi@redhat.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6191 c046a42c-6fe2-441c-8c8c-71466251a162