CVE-2025-40356 spi: rockchip-sfc: Fix DMA-API usage

In the Linux kernel, the following vulnerability has been resolved: spi: rockchip-sfc: Fix DMA-API usage Use DMA-API dmamapsingle call for getting the DMA address of the transfer buffer instead of hacking with virttophys. This fixes the following DMA-API debug warning: ------------ cut here...