Update to commit f21949c1 ("PCI/doc:Update
obsolete pci_set_dma_mask() references")

05b0ebd0 ("PCI/doc: cleanup references to
the legacy PCI DMA API")
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Wu XiangCheng <bobwxc@email.cn>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/bccb98a1c6706ecfd4aaba8c27f1c64024e1c139.1658983157.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>