net: MAINTAINERS: Demote Qualcomm IPA to "maintained"

To the best of my knowledge, Alex Elder is not being paid to support
Qualcomm IPA networking drivers, so drop the status from "supported" to
"maintained".

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Alex Elder <elder@kernel.org>
Link: https://patch.msgid.link/20240730104016.22103-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>