Intel-IOMMU.txt: standardize document format

Each text file under Documentation follows a different
format. Some doesn't even have titles!

Change its representation to follow the adopted standard,
using ReST markups for it to be parseable by Sphinx:

This file is almost in the right format. It only needed to
convert a list to bulleted list and to use the right markup
for literal blocks.

Signed-off-by: Mauro Carvalho Chehab <[e-mail]>
Signed-off-by: Jonathan Corbet <[e-mail]>

Documentation/Intel-IOMMU.txt

···
+===================
 Linux IOMMU Support
 ===================
 
···
 
 Some Keywords
 
-DMAR - DMA remapping
-DRHD - DMA Remapping Hardware Unit Definition
-RMRR - Reserved memory Region Reporting Structure
-ZLR  - Zero length reads from PCI devices
-IOVA - IO Virtual address.
+- DMAR - DMA remapping
+- DRHD - DMA Remapping Hardware Unit Definition
+- RMRR - Reserved memory Region Reporting Structure
+- ZLR  - Zero length reads from PCI devices
+- IOVA - IO Virtual address.
 
 Basic stuff
 -----------
···
 unity mappings for these regions for these devices to access these regions.
 
 How is IOVA generated?
----------------------
+----------------------
 
 Well behaved drivers call pci_map_*() calls before sending command to device
 that needs to perform DMA. Once DMA is completed and mapping is no longer
···
 ACPI: DMAR (v001 A M I  OEMDMAR  0x00000001 MSFT 0x00000097) @ 0x000000007f5b5ef0
 
 When DMAR is being processed and initialized by ACPI, prints DMAR locations
-and any RMRR's processed.
+and any RMRR's processed::
 
-ACPI DMAR:Host address width 36
-ACPI DMAR:DRHD (flags: 0x00000000)base: 0x00000000fed90000
-ACPI DMAR:DRHD (flags: 0x00000000)base: 0x00000000fed91000
-ACPI DMAR:DRHD (flags: 0x00000001)base: 0x00000000fed93000
-ACPI DMAR:RMRR base: 0x00000000000ed000 end: 0x00000000000effff
-ACPI DMAR:RMRR base: 0x000000007f600000 end: 0x000000007fffffff
+	ACPI DMAR:Host address width 36
+	ACPI DMAR:DRHD (flags: 0x00000000)base: 0x00000000fed90000
+	ACPI DMAR:DRHD (flags: 0x00000000)base: 0x00000000fed91000
+	ACPI DMAR:DRHD (flags: 0x00000001)base: 0x00000000fed93000
+	ACPI DMAR:RMRR base: 0x00000000000ed000 end: 0x00000000000effff
+	ACPI DMAR:RMRR base: 0x000000007f600000 end: 0x000000007fffffff
 
 When DMAR is enabled for use, you will notice..
 
···
 Fault reporting
 ---------------
 
-DMAR:[DMA Write] Request device [00:02.0] fault addr 6df084000
-DMAR:[fault reason 05] PTE Write access is not set
-DMAR:[DMA Write] Request device [00:02.0] fault addr 6df084000
-DMAR:[fault reason 05] PTE Write access is not set
+::
+
+	DMAR:[DMA Write] Request device [00:02.0] fault addr 6df084000
+	DMAR:[fault reason 05] PTE Write access is not set
+	DMAR:[DMA Write] Request device [00:02.0] fault addr 6df084000
+	DMAR:[fault reason 05] PTE Write access is not set
 
 TBD
 ----