[PATCH] i386: let REGPARM no longer depend on EXPERIMENTAL

REGPARM has already gotten much testing, what about removing the
dependency on EXPERIMENTAL?

Additionally, this patch does:
- remove the useless "default n"
- remove note regarding binary only modules (nowadays, there are even
  some binary only modules compiled with REGPARM=y available)

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>