pcmcia: avoid pccard_validate_cis failure in resume callpath

If the PCMCIA CIS changed before a resume event (e.g. due to
a card exchange while being suspended, possibly also during
a call to "pccardctl reset"), also set the function count to
zero so that the subsequent call to pccard_validate_cis() does
not fail.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>