isci: move core/controller to host

Now that the data structures are unified unify the implementation in
host.[ch] and cleanup namespace pollution.

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/scsi/isci/probe_roms.c

@@ -32,7 +32,6 @@
 
 #include "isci.h"
 #include "task.h"
-#include "sci_environment.h"
 #include "probe_roms.h"
 
 struct efi_variable {