media: sti/bdisp: don't pass GFP_DMA32 to dma_alloc_attrs

The DMA API does its own zone decisions based on the coherent_dma_mask.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>