ARM: dts: msm: adjust 8x12 skuab HX8389B mipi clock to 240.42MHZ

Currently, mipi clocking running at 276MHZ which affects GSM signal
on 8x12 SKUAB Himax8389b panel. Changing the mipi clock frequency
to 240.42MHZ to avoid RF interference.

Change-Id: I3fb3d3d3303464056cc71f48b6356698195c4b55
Signed-off-by: Shuo Yan <shuoy@codeaurora.org>