mxser: renumber mxser_cards

After the ISA cards removal in the previous patch, the mxser_cards array
has holes in it. So renumber the array while updating PCI device's
driver_data.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210618061516.662-3-jslaby@suse.cz


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>