ARM: dts: msm: Use Q6 SMEM size entry

Added code changes to use the new "qcom,ipa-q6-smem-size"
entry. To configure SMEM partition according dtsi entry
specified the size

Change-Id: I4e52f19f48f456a5b1355139b522ad2fe8e2ef53
Acked-by: Ashok Vuyyuru <avuyyuru@qti.qualcomm.com>
Signed-off-by: Mohammed Javid <mjavid@codeaurora.org>