media: venus: Include io.h for memremap()

This file uses memremap() now, so we should include io.h instead of
relying on any sort of implicit include elsewhere.

Cc: Dikshita Agarwal <dikshita@codeaurora.org>
Fixes: 0ca0ca98 ("media: venus: core: add support to dump FW region")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Fritz Koenig <frkoenig@chromium.org>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>