wlantest: Allow additional PTKs to be specified from a file

wlantest: Allow additional PTKs to be specified from a file

A text file with a hexdump of PTK (KCK|KEK=TK with 48 octets for CCMP or
64 octets for TKIP or alternative 16 or 32 octet TK for CCMP/TKIP) can
now be read from a file specified with the -T command line argument. If
the current known PTK fails to decrypt a frame (or if no current PTK is
known) all listed PTKs are iterated to see if any of them matches.

Signed-hostap: Jouni Malinen <j@w1.fi>