arm64: dts: renesas: r8a774a1: Create thermal zone to support IPA

Setup a thermal zone driven by SoC temperature sensor. Create passive trip
points and bind them to CPUFreq cooling device that supports power
extension.

Based on work by Dien Pham <dien.pham.ry@renesas.com> for r8a7796 SoC.

Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>