Add param ops struct for hvc_iucv driver.

Today's next 20091117 build failed on s390 with

drivers/char/hvc_iucv.c:1331: error: 'param_ops_vmidfilter' undeclared here (not in a function)
make[2]: *** [drivers/char/hvc_iucv.o] Error 1

Most probably caused by commit 684a6d340b8a5767db4670031b0f39455346018a
(param:param_ops) which introduced a param_ops structure.

The following compile tested patch adds a param_ops structure for hvc_iucv.

Signed-off-by: Sachin Sant <sachinp@in.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>