soc: mediatek: mtk-devapc: Fix leaking IO map on driver remove

Driver removal should fully clean up - unmap the memory.

Fixes: 0890beb2 ("soc: mediatek: add mt6779 devapc driver")
Cc: stable@vger.kernel.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20250104142012.115974-2-krzysztof.kozlowski@linaro.org


Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>