ARM: dts: msm: add sdhc node bus vectors for apq8084

Add bus vectors to use with the bus scaling driver for sdhc nodes.
This will ensure that the is a minimum amount of perofrmance garaunteed
by the driver.

Change-Id: Icff5c2db8a9bb0b45bc7d9c540917c986fa4e1da
Signed-off-by: Krishna Konda <kkonda@codeaurora.org>