package/libopenssl: m68x use SMALL_FOOTPRINT mode

OPENSSL_SMALL_FOOTPRINT mode selects alternate paths in the sha512 and
blake2 algorithms which resolves a assembler issue like the following.

/tmp/ccfnLhKQ.s: Assembler messages:
/tmp/ccfnLhKQ.s:11167: Error: value -32790 out of range
make[2]: *** [crypto/blake2/blake2b.o] Error 1

This issue was found after the OpenSSL1.1.x bump.

Fixes
http://autobuild.buildroot.net/results/533e817695cde321b725145112cfd83c092d9d75

Upstream ticket
https://github.com/openssl/openssl/issues/8190



Signed-off-by: Matthew Weber <matthew.weber@rockwellcollins.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>