1a) fixes a too short memory allocation on 64bit (DRVCONFIGINFO is 20 byte
    large while only 16 bytes were allocated)
1b) incidentally, removes a bunch of GCC11 warnings (generated by 1a)
2)  introduces DRVCONFIGINFOEX (note, in SDK, it's defined in mmiscapi.h;
    since it doesn't exist yet in Wine, I added the structure to
    mmsystem.h, where DRVCONFIGINFO already exists)
3)  initializes the missing field

Note: my testing don't show on Win10's msacm32 that DRV_CONFIGURE uses the
DRVCONFIGINFOEX structure.
So, maybe (wild guess here), the extended structure is only used
when the driver is linked to some hardware.
Signed-off-by: Eric Pouech <eric.pouech@gmail.com>
Signed-off-by: Andrew Eikum <aeikum@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>