dt-bindings: thermal: rcar-gen3-thermal: Support five TSC nodes on r8a779a0

When adding support for V3U (r8a779a0) it was incorrectly recorded it
supports four nodes, while in fact it supports five. The fifth node is
named TSC0 and breaks the existing naming schema starting at 1. Work
around this by separately defining the reg property for V3U and others.

Restore the maximum number of nodes to three for other compatibles as
it was before erroneously increasing it for V3U.

Fixes: d7fdfb65 ("dt-bindings: thermal: rcar-gen3-thermal: Add r8a779a0 support")
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210310110716.3297544-1-niklas.soderlund+renesas@ragnatech.se