MIPS: mobileye: eyeq6h-epm6: Use eyeq6h in the board device tree

There is currently no eyeq6 compatible string defined in the binding
documentation. Only eyeq6h version is defined, so let's use it.

Note that there are actually no codes relying on eyeq6h; the purpose
of this patch is mainly to be coherent with the documentation.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>