dmaengine: ioat: depends on !UML

dmaengine: ioat: depends on !UML

[ Upstream commit bbac7a92a46f0876e588722ebe552ddfe6fd790f ]

Now that UML has PCI support, this driver must depend also on
!UML since it pokes at X86_64 architecture internals that don't
exist on ARCH=um.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/20210809112409.a3a0974874d2.I2ffe3d11ed37f735da2f39884a74c953b258b995@changeid
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>