ARM: dts: msm: Update USB bus voting to allow low svs on SDM845

USB bus voting of 800Mbps is preventing low svs with USB headset
usecase as gcc_ddrss_sys_noc_sf_axi_clk is running at 200MHz. VCD
mechanism is using pre-defined ratio to configure SYS NOC clock
frequency. Hence based on this ratio, it is required to reduce USB
bus voting as 700Mbps to get gcc_ddrss_sys_noc_sf_axi_clk at 100MHz
which allows low svs on SDM845.

CRs-Fixed: 2087544
Change-Id: I82bd634380f5d615978fe2d6b3e8c1df081f4666
Signed-off-by: Mayank Rana <mrana@codeaurora.org>