Replace PTKSA cache inline stubs with wrapper function stubs

Replace PTKSA cache inline stubs with wrapper function stubs

PTKSA cache API is included in libpasn.so used by external modules,
e.g., Wi-Fi Aware. To avoid dependency on CONFIG_PTKSA_CACHE define for
the external modules at compile time, remove PTKSA cache static inline
functions from the header file and add wrapper function stubs.

Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>