ARM: dts: msm: decrease CPU DMA latency for msm8994

Decrease the CPU DMA latency value for msm8994 from
701 to 301 for sdhc devices. This change improves
performance of IO workloads by over 50%.

Change-Id: I9a6090c507beb1e7a769a64739405fdb387654f6
Signed-off-by: Vince Leung <vincentl@codeaurora.org>