Adds link for KVM-KSM

Adds link to KVM: Kernel Samepage Merging
to link section at end of chatper 40 (ch051).
No link added for XEN-TPS as this section of
chapter 40 needs further review - new bug to follow.

Made edits for clarity (diane fleming)

Change-Id: Ieeb5f83260120cb66238adc5338955d5fbc59dce
Closes-Bug: #1317853
Merge "Adds link for KVM-KSM"