ARM: dts: msm: Link 8939 gpu dtsi files

Link different hardware versions of msm8939-gpu.dtsi files
to their respective msm8939.dtsi

Change-Id: Ide342c5ae388ea11412dae7f17f3a447263ad4d4
Signed-off-by: Anshuman Dani <adani@codeaurora.org>
Signed-off-by: Sridhar Gujje <sgujje@codeaurora.org>
Signed-off-by: Bharat Pawar <bpawar@codeaurora.org>
Signed-off-by: Nirmal Abraham <nabrah@codeaurora.org>