linux-imx

riscv: select DMA_DIRECT_OPS instead of redefining it

DMA_DIRECT_OPS is defined in lib/Kconfig, so don't duplicate it in
arch/riscv/Kconfig.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>