The default monitor that ships with B850v3 requires a 65MHz pixel clock.
65MHz can not be achieved using PLL3 (480MHz/7=68.5MHz). Hence set the
LDB_DIx clock source to PLL5. Since PLL5 is already in use by IPU1_DIx,
set the clock source for IPU1_DIx to PLL2_PFD2 to allow simultaneous
display on both LVDS and HDMI interface.