libsamplerate: Build as internal library

Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D51666

share/mk/src.libnames.mk

@@ -72,6 +72,7 @@ _INTERNALLIBS=	\
 		pfctl \
 		pkgecc \
 		pmcstat \
+		samplerate \
 		sl \
 		sm \
 		smdb \
@@ -747,6 +748,9 @@ LIBC_NOSSP_PIC?=	${LIBC_NOSSP_PICDIR}/libc_nossp_pic.a
 LIBSYS_PICDIR=	${_LIB_OBJTOP}/lib/libsys
 LIBSYS_PIC?=	${LIBSYS_PICDIR}/libsys_pic.a
 
+LIBSAMPLERATEDIR?=	${_LIB_OBJTOP}/lib/libsamplerate
+LIBSAMPLERATE?=	${LIBSAMPLERATEDIR}/libsamplerate${PIE_SUFFIX}.a
+
 # Define a directory for each library.  This is useful for adding -L in when
 # not using a --sysroot or for meta mode bootstrapping when there is no
 # Makefile.depend.  These are sorted by directory.