ARM: dts: Rename msm8974-v2-2* to msm8974-v2.2* for clarity

Make it clear these files are for version 2.2 of 8974 silicon.
Also update the version numbers in the model strings while we're
at it.

Change-Id: Ice42e89a8fd6cf7492aa9a14c991827b0833770e
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>