ARM: msm: dts: Remove unwanted DDR bw values

removal of the non-Fmax clock-rates from allowable
clock-rates table because these intermediate
clock-rates are only adding unnecessary complexity and
no real benefit to power.

Change-Id: Ib8f7d14b3f5e02623ffdf51766527f637a4779a1
Signed-off-by: Chandrasekhar Mattaparthy <cmatta@codeaurora.org>