target: msm8996: improve DSI PLL's performance

To improve performance margin for DSI's PLL at cold
temperature case, the value of DSIPHY_PLL_PLL_ICPMSET
should be changed from 0x24 to 0x3f for DSI0 and DSI1.

CRs-Fixed: 2198545
Change-Id: I9d8353b0217b53877a80e6a1432eb0c4e3eb772c
Signed-off-by: Guchun Chen <guchunc@codeaurora.org>