qeth: qeth_core_main make local functions static

This patch makes some global functions static and removes
the prototypes from the header file.
Also function qeth_query_card_info is not exported anymore,
there is no external user for it, this function should never
have been exported in the first place.

Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: Frank Blaschka <blaschka@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>