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 dma_map_single() call for getting the DMA address of the
transfer buffer instead of hacking with virt_to_phys().

This fixes the following DMA-API debug warning:
------------[ cut here ]------------
DMA-API: rockchip-sfc fe300000.spi: device driver tries to sync DMA memory it has not allocated [device address=0x000000000cf70000] [size=288 bytes]
WARNING: kernel/dma/debug.c:1106 at check_sync+0x1d8/0x690, CPU#2: systemd-udevd/151
Modules linked in: ...
Hardware name: Hardkernel ODROID-M1 (DT)
pstate: 604000c9 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : check_sync+0x1d8/0x690
lr : check_sync+0x1d8/0x690
..
Call trace:
check_sync+0x1d8/0x690 (P)
debug_dma_sync_single_for_cpu+0x84/0x8c
__dma_sync_single_for_cpu+0x88/0x234
rockchip_sfc_exec_mem_op+0x4a0/0x798 [spi_rockchip_sfc]
spi_mem_exec_op+0x408/0x498
spi_nor_read_data+0x170/0x184
spi_nor_read_sfdp+0x74/0xe4
spi_nor_parse_sfdp+0x120/0x11f0
spi_nor_sfdp_init_params_deprecated+0x3c/0x8c
spi_nor_scan+0x690/0xf88
spi_nor_probe+0xe4/0x304
spi_mem_probe+0x6c/0xa8
spi_probe+0x94/0xd4
really_probe+0xbc/0x298
...