ALSA: pcm: Use dma_mmap_coherent() on x86, too

We avoided the explicit use of dma_mmap_coherent() on x86 because of a
spurious warning in x86 APT code in the past.  However, this blindly
assumes that the pages allocated via dma_alloc_coherent() on x86 are
the ones convertible via virt_to_page() (that is used in the default
mmap handler), and it's no longer true; with the indirect DMA ops,
this can be handled differently.  The only certain way for doing mmap
such pages is the dma_mmap_coherent(), and the warning seems already
gone in the recent code, so let's use it consistently.

Link: https://lore.kernel.org/r/20200615160045.2703-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/pcm_native.c

@@ -3713,7 +3713,6 @@ int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream,
 				area->vm_end - area->vm_start, area->vm_page_prot);
 	}
 #endif /* CONFIG_GENERIC_ALLOCATOR */
-#ifndef CONFIG_X86 /* for avoiding warnings arch/x86/mm/pat.c */
 	if (IS_ENABLED(CONFIG_HAS_DMA) && !substream->ops->page &&
 	    (substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV ||
 	     substream->dma_buffer.dev.type == SNDRV_DMA_TYPE_DEV_UC))
@@ -3722,7 +3721,6 @@ int snd_pcm_lib_default_mmap(struct snd_pcm_substream *substream,
 					 substream->runtime->dma_area,
 					 substream->runtime->dma_addr,
 					 substream->runtime->dma_bytes);
-#endif /* CONFIG_X86 */
 	/* mmap with fault handler */
 	area->vm_ops = &snd_pcm_vm_ops_data_fault;
 	return 0;