remoteproc: qcom: pas: Mark va as io memory

The pas driver remaps the entire carveout region using the dev_ioremap_wc()
call, which is then used in the adsp_da_to_va() calls made by the rproc
framework. This change marks the va returned by this call as an iomem va.

Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
Signed-off-by: Sibi Sankar <quic_sibis@quicinc.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1657022900-2049-3-git-send-email-quic_sibis@quicinc.com