[SCSI] aic94xx: Set lldd_max_execute_num in sas_ha

The aic94xx module has a parameter that looks like it should set
lldd_max_execute_num in the sas_ha, but it never sets this value.  Either
we should set it or remove the parameter.  This allows us to enable task
collector mode for this driver, though it is still off by default.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>