ahci: Fix data abort on multiple scsi resets.

Commit 2faf5fb8 introduced a regression that causes a data
abort when running scsi init followed by scsi reset.

There are 2 problems with the original commit
1) ALLOC_CACHE_ALIGN_BUFFER() allocates memory on the stack but is
assigned to ataid[port] and used by other functions.
2) The function ata_scsiop_inquiry() tries to free memory which was
never allocated on the heap.

Fix these problems by using tmpid as a temporary cache aligned buffer.
Allocate memory separately for ataid[port] and re-use it if required.

Fixes: 2faf5fb8 (ahci: Fix cache align error messages)

Reported-by: Eli Nidam <elini@marvell.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>