ARM: dts: msm: update PCIe clock frequencies for SDM845

With the new addition of PCIe sleep clock in PCIe bus driver,
update PCIe clock frequency tables for SDM845.

Change-Id: I680874212f1b24723a2b4a8ebf84803315687eff
Signed-off-by: Tony Truong <truong@codeaurora.org>