[SCSI] bfa: remove all OS wrappers

Remove OS wrapper functions/macros, and as a result remove bfa_os_inc.h.

Signed-off-by: Maggie Zhang <xmzhang@brocade.com>
Signed-off-by: Jing Huang <huangj@brocade.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>