dt-bindings: w1: Add AMD AXI w1 host and MAINTAINERS entry

Add YAML DT schema for the AMD AXI w1 host IP.

This hardware guarantees protocol timing for driving off-board devices
such as thermal sensors, proms, etc using the 1wire protocol. The IP
has a register to detect hardware version and so the binding does not
have an explicit version number.

Add MAINTAINERS entry for DT schema.

Co-developed-by: Thomas Delev <thomas.delev@amd.com>
Signed-off-by: Thomas Delev <thomas.delev@amd.com>
Signed-off-by: Kris Chaplin <kris.chaplin@amd.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20231107180814.615933-2-kris.chaplin@amd.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>