clk: qcom: clk-cpu-osm: Add OSM clock driver support for SM6150

SM6150 has 6-2 cores configuration, but current design of OSM
clock driver is based on 4-4 cores configuration. Add the necessary
changes to support 6-2 cores configuration.

Change-Id: Ic5a53367a15eb1b43dad71df2f43b9906c2c0b43
Signed-off-by: Odelu Kukatla <okukatla@codeaurora.org>