MtrrSetMemoryAttributesInMtrrSettings() is a batch-set API.
When setting multiple ranges of memory attributes, the single-set
API (MtrrSetMemoryAttributeInMtrrSettings and MtrrSetMemoryAttribute)
may fail, but batch-set API may succeed.
Add comments to recommend caller to use batch-set API when setting
multiple ranges.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Ming Shao <ming.shao@intel.com>