x86: Make calgary_iommu_init() static

This makes calgary_iommu_init() static and moves it to remove
the forward declaration.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: muli@il.ibm.com
LKML-Reference: <20091114212603U.fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>