arm64: dts: qcom: sdm845-mtp: Add nodes for USB

Set the various nodes to "okay" and hook up the regulators.

NOTE: For now the main USB port (the one that goes out the Type C
connector) is forced to host.  Eventually someone will need to get the
Type C detection hooked up and get this all integrated with the
PMI8998 PMIC.  The reason for forcing to "host" in the meantime is
that this will leave us with one "host" and one "peripheral" port.

In order for host mode this to work, we assume that the bootloader
left things configured enough for us.  Apparently the magic for that
is is to do these writes on pmi8998:
- pm_comm_write_byte(2, 0x1153, 0x2C, 0);
- pm_comm_write_byte(2, 0x1152, 0x07, 0);
- pm_comm_write_byte(2, 0x1140, 0x00, 0);
- pm_comm_write_byte(2, 0x1140, 0x01, 0);

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>