arm/dt: msm8974: Modify cpufreq-table

Currently 1.26 GHz and 1.49 GHz in the cpufreq-table for 8974
map to 800 MHz DDR. With this change the above frequencies
now get mapped to 614 MHz DDR. This change maps the above
two frequencies to lower DDR and will thereby help save power
for use cases which spend majority of time at above frequencies.

Change-Id: Id56dac3555be3e2eb8425e809dffbbcec9e8d088
Signed-off-by: Dilip Gudlur <dgudlur@codeaurora.org>