ARM: dts: msm: Remove dummy Fmax entries in clock node for 8939

Dummy Fmax enties have added to speed_bin 4 to find a common max
voltage corner. Remove the dummy entries as the support to find
common max corner value has been added in clock driver.

Change-Id: I278ca78e39c26b94fe2dee7a11e27d34d7ae4745
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>