lib/dma-debug.c: make locking work for RT

lib/dma-debug.c: make locking work for RT

Interrupt enable/disabled with spinlock is not a valid operation for RT
as it can make executing tasks sleep from a non-sleepable context.  So
convert it to spin_lock_irq[save, restore].

Link: http://lkml.kernel.org/r/1492065666-3816-1-git-send-email-pagupta@redhat.com
Signed-off-by: Pankaj Gupta <pagupta@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ville Syrjl <ville.syrjala@linux.intel.com>
Cc: Miles Chen <miles.chen@mediatek.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>