mpt2sas, mpt3sas: Remove SCSI_MPTXSAS_LOGGING entry from Kconfig

Currently there is a logging level option provided for each of our
drivers in the kernel configuration utility. Users can enable this
option to get more verbose information. By default it is enabled.

Only when this option is enabled will the functions which display the
required information get compiled in.

As we are merging the both drivers we can no longer provide this
configuration option. Remove the SCSI_MPTXSAS_LOGGING entry from Kconfig
and unconditionally enable logging (by removing the #ifdef
CONFIG_SCSI_MPT3SAS_LOGGING preprocessor check conditions) so that all
functions which are defined to display more verbose information get
compiled in.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>