ARM: dts: msm: Rename the smmu dtsi file name for atoll

Generally the name of smmu dtsi is same as the name of main dtsi.
Do the change accordingly.

Change-Id: I18df3f3c566073060e81169fd1d6d93fd2472829
Signed-off-by: Zhenhua Huang <zhenhuah@codeaurora.org>