ARM: dts: qcom: Add chosen node and update boot args for Kona

RCU's grace period delays can have impact on the boot time requirements.
Also, RCU callbacks can be offloaded to all the CPUs to avoid latencies.
So, add chosen node and update the boot command line arguments with the
required RCU flags.

Change-Id: Iab0982b3f039e106a9ab526fd5c4c476037a1be3
Signed-off-by: Venkata Narendra Kumar Gutta <vnkgutta@codeaurora.org>