[SCSI] mvsas: fix hot plug handling and IO issues

[SCSI] mvsas: fix hot plug handling and IO issues

This patch adds a bunch of fixes

1. Reduce sg table size to 64 (SG_MX) instead of default SG_ALL
2. clear task lists on phy down events
3. release all tasks on port deformation
4. release current task for device gone notification
5. Add sata abort handing
6. Add 10ms delay to each port reset (currently done serially and with
   interrupts disabled)

[jejb: whitespace fixes and clean ups plus added description
       added dummy 94xx_clear_srs_irq function just to prevent the
       mismatch in the mvs_dispatch structure killing 94xx cards]
Signed-off-by: Srinivas <satyasrinivasp@hcl.in>
Cc: Andy Yan <ayan@marvell.com>
Cc: qswang@marvell.com
Cc: jfeng@marvell.com
Signed-off-by: James Bottomley <James.Bottomley@suse.de>