arm64: dts: qcom: sc7180-trogdor: Simplify spi0/spi6 labeling

We had to do this spi0/spi6 flip-flop on trogdor-r0 because the spi
buses got swizzled between r0 and r1. The swizzle stopped after r1, but
we kept this around to support either hardware possibility and to keep
trogdor-r0 working.

trogdor-r0 isn't supported upstream, so this swizzle is not doing
anything besides making a pattern that others tryt  to copy for the EC and
H1 nodes. Let's remove it and simplify the dts files.

Cc: "Joseph S. Barrera III" <joebar@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220427020339.360855-3-swboyd@chromium.org