package/strace: fix build for mips

package/strace: fix build for mips

Upstream changes in mips specific code of the last release broke build
for that target. Add a patch that restores build.

Fixes:
http://autobuild.buildroot.net/results/858/8585e75df6462b6d07476a81982e88ec81655c8b/
http://autobuild.buildroot.net/results/b2f/b2f24976ddda1adc9b9ba3d9bfb7167721814f78/
http://autobuild.buildroot.net/results/031/0313245fe555e0c0890c3f475bf6586db23535ed/

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>