pc: Fix CMOS info for drives defined with -device

Drives defined with -drive if=ide get get created along with the IDE
controller, inside machine->init().  That's before cmos_init().
Drives defined with -device get created during generic device init.
That's after cmos_init().  Because of that, CMOS has no information on
them (type, geometry, translation).  Older versions of Windows such as
XP reportedly choke on that.

Split off the part of CMOS initialization that needs to know about
-device devices, and turn it into a reset handler, so it runs after
device creation.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
(cherry picked from commit c0897e0c)