MAINTAINERS: Drop Robert Jones

Emails to Robert Jones bounce ("550 5.2.1 The email account that you
tried to reach is disabled").

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-By: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20220808111113.71890-1-krzysztof.kozlowski@linaro.org