dmaengine: dma-axi-dmac: Drop struct clk from main struct

dmaengine: dma-axi-dmac: Drop struct clk from main struct

There's no reason to keep struct clk in struct axi_dmac. Hence, use a
local clk variable in .probe() and drop it from struct axi_dmac.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260424-dma-dmac-handle-vunmap-v4-3-90f43412fdc0@analog.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>