sparc: cleanup references to deprecated .text.init* sections.

The section .text.init.refok is deprecated and __REF (.ref.text)
should be used in assembly files instead.  This patch cleans up a few
uses of .text.init.refok in the sparc architecture.

Also fix a reference to .text.init in a comment that wasn't updated to
.init.text.

Signed-off-by: Tim Abbott <tabbott@mit.edu>
Cc: David S. Miller <davem@davemloft.net>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>