MAINTAINERS: Update the entry for pinctrl maintainers

Update the entry for pinctrl bindings maintainer as the
current one checks only in the .txt files.

Signed-off-by: Rohit Agarwal <quic_rohiagar@quicinc.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/1684425432-10072-3-git-send-email-quic_rohiagar@quicinc.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>