ARM: dts: msm: Enable host mode interrupt moderation for SDXPRAIRIE

XHCI allows interrupt moderation using imod_interval at 250ns
increments. It is useful to bring down CPU usage on targets
that are having single core.

Change-Id: I90cc45091c7b110463ac7e134c0fe06accf4e26d
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>