i386/pc: pc_basic_device_init(): delegate FDC creation request

i386/pc: pc_basic_device_init(): delegate FDC creation request

This patch introduces no observable change, but it allows the callers of
pc_basic_device_init(), ie. pc_init1() and pc_q35_init(), to request (or
not request) the creation of the FDC explicitly.

At the moment both callers pass constant create_fdctrl=true (hence no
observable change).

Assuming a board passes create_fdctrl=false, "floppy" will be NULL on
output, and (beyond the FDC not being created) that NULL will be passed on
to pc_cmos_init(). Luckily, pc_cmos_init() already handles that case.

Cc: Markus Armbruster <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Gerd Hoffmann <[email protected]>
Cc: John Snow <[email protected]>
Cc: "Gabriel L. Somlo" <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Kevin Wolf <[email protected]>
Cc: [email protected]
Signed-off-by: Laszlo Ersek <[email protected]>
Reviewed-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Michael S. Tsirkin <[email protected]>
Reviewed-by: Markus Armbruster <[email protected]>