treewide: replace '---help---' in Kconfig files with 'help'

Since commit 84af7a6194 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

fs/romfs/Kconfig

@@ -2,7 +2,7 @@
 config ROMFS_FS
 	tristate "ROM file system support"
 	depends on BLOCK || MTD
-	---help---
+	help
 	  This is a very small read-only file system mainly intended for
 	  initial ram disks of installation disks, but it could be used for
 	  other read-only media as well.  Read