linuxkm/lkcapi_sha_glue.c: fix export/import for HMAC:

* add to struct km_sha_hmac_pstate members desc_list_lock, desc_list, export_list, and export_list_len;
* add struct km_sha_hmac_export_state;
* add km_hmac_alloc_tstate(), km_hmac_export(), km_hmac_import(), km_hmac_test_export_import();
* and update km_hmac_*() and WC_LINUXKM_HMAC_IMPLEMENT(() to implement.

Author: douzzer