Fix compile error:
drivers/dma/ralink-gdma.c: In function 'gdma_dma_config':
drivers/dma/ralink-gdma.c:197:40: error: 'struct dma_slave_config' has no member named 'slave_id'
197 | chan->slave_id = config->slave_id;
| ^~
drivers/dma/ralink-gdma.c:206:40: error: 'struct dma_slave_config' has no member named 'slave_id'
206 | chan->slave_id = config->slave_id;
| ^~
make[8]: *** [scripts/Makefile.build:243: drivers/dma/ralink-gdma.o] Error 1
ref: https://lore.kernel.org/all/20211122222203.4103644-1-arnd@kernel.org/
Signed-off-by: Shiji Yang <yangshiji66@qq.com>
The gdma driver has been removed from the upstream. Let's move it
to the local files. This patch also removed unsupported compatible
string and sub-target.
Signed-off-by: Shiji Yang <yangshiji66@qq.com>
