scripts/spelling.txt: add "followings" pattern and fix typo instances

Fix typos and add the following to the scripts/spelling.txt:

  followings||following

While we are here, add a missing colon in the boilerplate in DT binding
documents.  The "you SoC" in allwinner,sunxi-pinctrl.txt was fixed as
well.

I reworded "as the followings:" to "as follows:" for
drivers/usb/gadget/udc/renesas_usb3.c.

Link: http://lkml.kernel.org/r/1481573103-11329-32-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/pci/quirks.c

@@ -3630,7 +3630,7 @@ static int __init pci_apply_final_quirks(void)
 fs_initcall_sync(pci_apply_final_quirks);
 
 /*
- * Followings are device-specific reset methods which can be used to
+ * Following are device-specific reset methods which can be used to
  * reset a single function if other methods (e.g. FLR, PM D0->D3) are
  * not available.
  */