Fix the following warning with explicit cast:

warning: implicit conversion from 'unsigned long long' to
'dma_addr_t' (aka 'unsigned int')
mhi_cntrl->iova_stop = DMA_BIT_MASK(info->dma_data_width);

Fixes: 855a70c1 ("bus: mhi: Add MHI PCI support for WWAN modems")
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>