ARM: dts: msm: Enable smmu for APQ8084

APQ8084 uses smmu for shared memory access with ADSP.
Hence smmu-enabled field has to be true for APQ8084 devices.
Remove audio HEAP as there is no need for this with SMMU
enabled.

Change-Id: If61f7a4f6287dfd3060660eb342dbacfbdc6afba
Signed-off-by: Banajit Goswami <bgoswami@codeaurora.org>