qxl: change rom size to 8192

This is a simpler solution to 869981, where migration breaks since qxl's
rom bar size has changed. Instead of ignoring fields in QXLRom, which is what has
actually changed, we remove some of the modes, a mechanism already
accounted for by the guest. The modes left allow for portrait and
landscape only modes, corresponding to orientations 0 and 1.
Orientations 2 and 3 are dropped.

Added assert so that rom size will fit the future QXLRom increases via
spice-protocol changes.

This patch has been tested with 6.1.0.10015. With the newer 6.1.0.10016
there are problems with both "(flipped)" modes prior to the patch, and
the patch loses the ability to set "Portrait" modes. But this is a
separate bug to be fixed in the driver, and besides the patch doesn't
affect the new arbitrary mode setting functionality.

Signed-off-by: Alon Levy <alevy@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit 038c1879a00153b14bce113315b693e8c2944fa9)
qxl: stop using non revision 4 rom fields for revision < 4

Signed-off-by: Alon Levy <alevy@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit e0ac6097b6cc24694e83ae61e80040177bb5a584)
qxl: Don't drop client capability bits

interface_set_client_capabilities() copies only the first few bits,
because it falls into a Classic C trap: you can declare a parameter
uint8_t caps[58], but the resulting parameter type is uint8_t *, not
uint8_t[58].  In particular, sizeof(caps) is sizeof(uint8_t *), not
the intended sizeof(uint8_t[58]).

Harmless, because the bits aren't used, yet.  Broken in commit
c10018d6.  Spotted by Coverity.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit 08688af04dc1137ac2f420b35c235183926b4a23)