SPARC64: ds driver: Make memory allocations ATOMIC and enhance debugging

SPARC64: ds driver: Make memory allocations ATOMIC and enhance debugging

This patch fixes the following issues:

1. BUG 25107317 - Kernel Panic: Watchdog HARD LOCKUP out of ds_cap_fini()
2. BUG 24787856 - Forward port 19811909 - Unnecessary
                  warning - ldom_req_sp_token

BUG 25107317 appears to be caused by the ds driver allocating memory using
the GFP_KERNEL flag (which can result in sleeping) while holding a spinlock.
This is a violation of rules and resulted in the panic.

To fix BUG 24787856, the error message in question was changed to a
printk_once() which will result in the message only appearing once
in the console log instead of repeatedly.

The debugging facility in the driver was also enhanced by adding 3 separate
debug levels for the ds driver debug messages.

Signed-off-by: Aaron Young <Aaron.Young@oracle.com>
Reviewed-by: Alexandre Chartre <Alexandre.Chartre@oracle.com>
Reviewed-By: Liam Merwick <Liam.Merwick@oracle.com>
Orabug: 25107317, 24787856
(cherry picked from commit f3bf272f0512120708a2966a7916b51c34efe56d)
Signed-off-by: Allen Pais <allen.pais@oracle.com>