x86: calgary: remove IOMMU_DEBUG

CONFIG_IOMMU_DEBUG has depends on CONFIG_GART_IOMMU:

config IOMMU_DEBUG
	bool "Enable IOMMU debugging"
	depends on GART_IOMMU && DEBUG_KERNEL
	depends on X86_64

So it's not useful to have CONFIG_IOMMU_DEBUG in Calgary IOMMU code,
which does the extra checking of the bitmap space management.

And Calgary uses the iommu helper for the bitmap space management now
so it would be better to have the extra checking feature in the iommu
helper rather than Calgary code (if necessary).

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: Joerg Roedel <joerg.roedel@amd.com>
Cc: alexisb@us.ibm.com
LKML-Reference: <20090414120827G.fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>