ipa: rename functions for consistency

As we are breaking builds by moving functions from libosmo-abis to
libosmocore anyway, we might as well give functions more appropriate
names.  ipaccess is a company, while IPA is the multiplex protocol, and
CCM is the protocol used for establishing identities on the IPA
multiplex.
diff --git a/src/gsm/Makefile.am b/src/gsm/Makefile.am
index 06b1f18..b8009ac 100644
--- a/src/gsm/Makefile.am
+++ b/src/gsm/Makefile.am
@@ -19,7 +19,7 @@
 			auth_core.c auth_comp128v1.c auth_comp128v23.c \
 			auth_milenage.c milenage/aes-encblock.c \
 			milenage/aes-internal.c milenage/aes-internal-enc.c \
-			milenage/milenage.c gan.c ipaccess.c
+			milenage/milenage.c gan.c ipa.c
 
 libosmogsm_la_LDFLAGS = $(LTLDFLAGS_OSMOGSM) -version-info $(LIBVERSION) -no-undefined
 libosmogsm_la_LIBADD = $(top_builddir)/src/libosmocore.la