libcrypto: compile all PIC objects with -DOPENSSL_PIC

This change modifies the libcrypto PIC objects to always compile with
`-DOPENSSL_PIC` to restore parity with the upstream build process. This
ensures that `-DOPENSSL_PIC` is used whenever building the auxiliary
shared objects. In this case, just the legacy provider (we no longer
distribute the fips provider).

MFC after:		2 weeks
Differential Revision:	https://reviews.freebsd.org/D44896

secure/lib/libcrypto/modules/Makefile.inc

@@ -4,6 +4,8 @@ SHLIBDIR=	${LIBDIR}/ossl-modules
 
 LCRYPTO_SRC=	${SRCTOP}/crypto/openssl
 
+PICFLAG+=	-DOPENSSL_PIC
+
 CFLAGS+=	-I${LCRYPTO_SRC}
 CFLAGS+=	-I${LCRYPTO_SRC}/include
 CFLAGS+=	-I${LCRYPTO_SRC}/providers/common/include