fix perl signal numbering for mips

fix perl signal numbering for mips

This is a followup to my 16 month old patch for perl signal numbering for mipsel:

  https://dev.openwrt.org/changeset/16539

This time for mips.  Tested on atheros (accton mr3201a).  Also
compared favorably to linux-2.6.git's arch/mips/include/asm/signals.h

The most obvious benefit is that forked children get reaped
appropriately in long-running perl processes.  Please apply.

http://www.personaltelco.net/~russell/mips-perl-signal.patch

Signed-off-by: Russell Senior <seniorr@aracnet.com>
git-svn-id: svn://svn.openwrt.org/openwrt/packages@23472 3c298f89-4303-0410-b956-a3cf2f4a3e73