ARM: dts: msm: increase adsp heap size for msm8974

For hevc hybrid codec, adsp heap size needs to be increased to
64MB to support 1080p video.

Change-Id: I3812cc2f0204f18fbade9ae41d8e784909055569
Signed-off-by: Arun Menon <avmenon@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>