ARM: dts: msm: Add /cpu nodes for fsm9900

Add the /cpu nodes and populate it with CPU-specific information
to comply with Device Tree specification for FSM9900.

Change-Id: Ib8685216260f4e1d35d3508789a21552b9ffa1ae
Acked-by: Kaushik Sikdar <ksikdar@qti.qualcomm.com>
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>