ARM: dts: msm: delete bootargs which kernel not support

The two bootargs sched_enable_hmp and sched_enable_power_aware are not
supported by kernel, so delete them on msm8953.

Change-Id: I4432b58698e8481c8a1b5d8a007446d3b9d9db4f
Signed-off-by: Teng Fei Fan <tengfei@codeaurora.org>