[PATCH] perform maintenance on Documentation/vm/hugetlbpage.txt

Updates to Documentation/vm/hugetlbpage.txt:

- there's no need to select HUGETLB_PAGE manually and it's no longer
  under the processor menu.  Update the text accordingly.

- fix typos and trim trailing whitespace.

Signed-Off-By: Muli Ben-Yehuda <mulix@mulix.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>