pam_unix: Add support for (gost-)yescrypt hashing methods.

pam_unix: Add support for (gost-)yescrypt hashing methods.

libxcrypt (v4.2 and later) has added support for the yescrypt
hashing method; gost-yescrypt has been added in v4.3.

* modules/pam_unix/pam_unix.8.xml: Documentation for (gost-)yescrypt.
* modules/pam_unix/pam_unix_acct.c: Use 64 bit type for control flags.
* modules/pam_unix/pam_unix_auth.c: Likewise.
* modules/pam_unix/pam_unix_passwd.c: Likewise.
* modules/pam_unix/pam_unix_sess.c: Likewise.
* modules/pam_unix/passverify.c: Add support for (gost-)yescrypt.
* modules/pam_unix/passverify.h: Use 64 bit type for control flags.
* modules/pam_unix/support.c: Set sane rounds for (gost-)yescrypt.
* modules/pam_unix/support.h: Add support for (gost-)yescrypt.