libcrypto: compile all PIC objects with -DOPENSSL_PIC

[ngie]

Summary

This change modifies the libcrypto PIC objects to always link with
-DOPENSSL_PIC to restore parity with the upstream build process. This
ensures that -DOPENSSL_PIC is used whenever building the auxiliary
shared objects, e.g., the fips provider, the legacy provider, etc.

[ngie]

Fix the change to properly append the CFLAG to PICFLAG and do it after including bsd.lib.mk to properly compile/link libcrypto.so.