dmaengine: lgm: Use builtin_platform_driver macro to simplify the code

Use the builtin_platform_driver macro to simplify the code, which is the
same as declaring with device_initcall().

Signed-off-by: Li Zetao <lizetao1@huawei.com>
Acked-by: Peter Harliman Liem <pliem@maxlinear.com>
Link: https://lore.kernel.org/r/20230815080250.1089589-1-lizetao1@huawei.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>