s390: qeth: address type mismatch warning

clang produces a harmless warning for each use for the qeth_adp_supported
macro:

drivers/s390/net/qeth_l2_main.c:559:31: warning: implicit conversion from enumeration type 'enum qeth_ipa_setadp_cmd' to
      different enumeration type 'enum qeth_ipa_funcs' [-Wenum-conversion]
        if (qeth_adp_supported(card, IPA_SETADP_SET_PROMISC_MODE))
            ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/s390/net/qeth_core.h:179:41: note: expanded from macro 'qeth_adp_supported'
        qeth_is_ipa_supported(&c->options.adp, f)
        ~~~~~~~~~~~~~~~~~~~~~                  ^

Add a version of this macro that uses the correct types, and
remove the unused qeth_adp_enabled() macro that has the same
problem.

Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>