buildroot

package/libscrypt: add patch to fix CFLAGS/LDFLAGS passing

Because Buildroot passes its own CFLAGS/LDFLAGS, this was overriding
the ones from the package Makefile, leading to build failures because
-fPIC was no longer being passed.

This commit fixes that by adding a patch that allows to keep the
package CFLAGS while passing additional ones through the make command
line. While doing this, it also removes a few hardcoded optimization
and hardening flags, leaving it to Buildroot to decide whether they
should be passed or not. This makes the workaround for stack protector
no longer needed.

Fixes:

  http://autobuild.buildroot.net/results/b25/b256d003d841e492da073788198203e7cbc834cf/

Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
[Thomas: tweak commit log and patch description.]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>