mtd: rawnand: qcom: stop using phys_to_dma()

Compile-testing this driver on x86 caused a link error:

ERROR: "__phys_to_dma" [drivers/mtd/nand/raw/qcom_nandc.ko] undefined!

The problem here is that the driver attempts to convert the physical
address into the DMA controller as a dma_addr_t and calls phys_to_dma()
to do the conversion.

The correct way to do the conversion is using the dma mapping interfaces.

Fixes: c76b78d8

 ("mtd: nand: Qualcomm NAND controller driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>