remoteproc: Fix the wrong default value of is_iomem

remoteproc: Fix the wrong default value of is_iomem

Currently the is_iomem is a random value in the stack which may
be default to true even on those platforms that not use iomem to
store firmware.

Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Fixes: 40df0a91b2a5 ("remoteproc: add is_iomem to da_to_va")
Reviewed-and-tested-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210910090621.3073540-3-peng.fan@oss.nxp.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>