ARM: dts: msm: Fix 8939 regulator file inclusion

The 8939 regulator file is being included in some top level device
files. This overwrites the board/target specific configuration applied
to some device nodes of regulator file in other board specific files.

CRs-Fixed: 825703
Change-Id: I8eb8516b44130f5673a2acfdea8b10cdd438838d
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>