Remove lingering build code referencing the crypto submodule

Remove code guarded by `USE_CRYPTO_SUBMODULE`. It's dead now that
crypto can no longer be a submodule.

In `library/Makefile`:

* Replace `$(CRYPTO_INCLUDE)` with the single include directory
  `-I../include`.
* Remove references to `$(OBJS_CRYPTO)` when it's in addition to the
  local objects (`*.o`) since `$(OBJS_CRYPTO)` is now a subset of the
  local objects.
* Merge modules that were duplicated between the mbedtls and the
  mbed-crypto repositories back into the single list for `OBJS_CRYPTO`.
diff --git a/library/Makefile b/library/Makefile
index 07247f1..e4f92e5 100644
--- a/library/Makefile
+++ b/library/Makefile
@@ -5,8 +5,7 @@
 WARNING_CFLAGS ?=  -Wall -Wextra
 LDFLAGS ?=
 
-CRYPTO_INCLUDES ?= -I../include
-LOCAL_CFLAGS = $(WARNING_CFLAGS) $(CRYPTO_INCLUDES) -D_FILE_OFFSET_BITS=64
+LOCAL_CFLAGS = $(WARNING_CFLAGS) -I../include -D_FILE_OFFSET_BITS=64
 LOCAL_LDFLAGS =
 
 ifdef DEBUG
@@ -73,7 +72,7 @@
 		dhm.o		ecdh.o		ecdsa.o		\
 		ecjpake.o	ecp.o				\
 		ecp_curves.o	entropy.o	entropy_poll.o	\
-		gcm.o		havege.o			\
+		error.o		gcm.o		havege.o	\
 		hkdf.o						\
 		hmac_drbg.o	md.o		md2.o		\
 		md4.o		md5.o				\
@@ -89,20 +88,9 @@
 		ripemd160.o	rsa_internal.o	rsa.o  		\
 		sha1.o		sha256.o	sha512.o	\
 		threading.o	timing.o			\
+		version.o	version_features.o		\
 		xtea.o
 
-# For files generated by the parent project (Mbed TLS) when building Mbed
-# Crypto as a submodule, ensure that the parent project instance is used.
-ifeq ($(USE_CRYPTO_SUBMODULE), 1)
-OBJS_CRYPTO += $(patsubst %.c,%.o, $(realpath ../../library/error.c))
-OBJS_CRYPTO += $(patsubst %.c,%.o, $(realpath ../../library/version.c))
-OBJS_CRYPTO += $(patsubst %.c,%.o, $(realpath ../../library/version_features.c))
-else
-OBJS_CRYPTO += error.o
-OBJS_CRYPTO += version.o
-OBJS_CRYPTO += version_features.o
-endif
-
 include ../3rdparty/Makefile.inc
 LOCAL_CFLAGS+=$(THIRDPARTY_INCLUDES)
 OBJS_CRYPTO+=$(THIRDPARTY_CRYPTO_OBJECTS)
@@ -221,9 +209,8 @@
 
 clean:
 ifndef WINDOWS
-	rm -f *.o libmbed* $(OBJS_CRYPTO)
+	rm -f *.o libmbed*
 else
 	if exist *.o del /Q /F *.o
 	if exist libmbed* del /Q /F libmbed*
-	if exist $(OBJS_CRYPTO) del /Q /F $(OBJS_CRYPTO)
 endif