Revert "build tomcrypt sha256 code as separate object"

This reverts commit e552d93a50.

Usign GCC version 5.4.0 20160609 the code was 3 times slower (probably due to missing inlining and other optimizations). The binary was also >15kB bigger.

Makefile

@@ -22,7 +22,7 @@ TARGET = pixiewps
 include $(SRCDIR)/crypto/tfm/sources.mak
 TFMSRC = $(patsubst ./%,$(SRCDIR)/crypto/tfm/%,$(TFM_SRCS))
 TFMOBJS = $(TFMSRC:.c=.o)
-TC_SRCS = ./aes_cbc.c ./aes.c ./sha256.c
+TC_SRCS = ./aes_cbc.c ./aes.c
 TCSRC = $(patsubst ./%,$(SRCDIR)/crypto/tc/%,$(TC_SRCS))
 TCOBJS = $(TCSRC:.c=.o)
 

src/crypto/hmac_sha256.c

@@ -5,7 +5,7 @@
 #ifdef USE_OPENSSL
 # include <openssl/sha.h>
 #else
-# include "tc/tomcrypt.h"
+# include "tc/sha256.c"
 # define SHA256_CTX hash_state
 # define SHA256_Init(x) do { sha256_init(x); } while(0)
 # define SHA256_Update(x, y, z) sha256_process(x, y, z)