ARM: dts: msm: Configure "qcom,sync-dly" to 800us for SDM660

Leaving LED_SYNC_DLY register to a default value of 200us
leads to OVP interrupts randomly during the brightness change.
The legacy driver configured this to 800us which does not exhibit
the OVP behavior.. Hence, configure the sync delay value
to 800us.

Change-Id: I84407a325dbcb51f77d53c6499f10df2f1b27d2a
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>