Revert "ARM: dts: msm: Set TXHSXVTUNE0 value to 10 for MSM8937"

This reverts commit 713549a8
which set TXHSXVTUNE0 value to 10 for MSM8937. But this override
was to be done only for SDM439. msm8937.dtsi could be included in
other platforms' files for which we do not want this change.
Hence revert the change.

Change-Id: Ibe834839a9cfa211945ebb004d4fa98f08c1e636
Signed-off-by: Ajay Agarwal <ajaya@codeaurora.org>