ARM: dts: msm: Update clockgating sequence for sdxhedgehog

The architectural ARM timers are not functional when the root clock is
gated off from the SPM sequence. This prevents the cores from waking up for
a timer interrupt. The ARM cores are capable of clock gating its own clock
during idle and provide similar power benefits.

Remove the sequence to gate the root clock from the SPM sequence.

Change-Id: I2dfaa4ff72f855ea80a77d3131c62c4f6e574e0f
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>