build: move sha256_sse4 into libbitcoin_crypto_base

Followup to discussion in bitcoin#29407.
Drops LIBBITCOIN_CRYPTO_SSE4.

src/Makefile.am

@@ -50,8 +50,6 @@ LIBBITCOIN_WALLET_TOOL=libbitcoin_wallet_tool.a
 endif
 
 LIBBITCOIN_CRYPTO = $(LIBBITCOIN_CRYPTO_BASE)
-LIBBITCOIN_CRYPTO_SSE4 = crypto/libbitcoin_crypto_sse4.la
-LIBBITCOIN_CRYPTO += $(LIBBITCOIN_CRYPTO_SSE4)
 if ENABLE_SSE41
 LIBBITCOIN_CRYPTO_SSE41 = crypto/libbitcoin_crypto_sse41.la
 LIBBITCOIN_CRYPTO += $(LIBBITCOIN_CRYPTO_SSE41)
@@ -582,20 +580,14 @@ crypto_libbitcoin_crypto_base_la_SOURCES = \
   crypto/sha1.h \
   crypto/sha256.cpp \
   crypto/sha256.h \
+  crypto/sha256_sse4.cpp \
   crypto/sha3.cpp \
   crypto/sha3.h \
   crypto/sha512.cpp \
   crypto/sha512.h \
   crypto/siphash.cpp \
   crypto/siphash.h
 
-# See explanation for -static in crypto_libbitcoin_crypto_base_la's LDFLAGS and
-# CXXFLAGS above
-crypto_libbitcoin_crypto_sse4_la_LDFLAGS = $(AM_LDFLAGS) -static
-crypto_libbitcoin_crypto_sse4_la_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS) -static
-crypto_libbitcoin_crypto_sse4_la_CPPFLAGS = $(AM_CPPFLAGS)
-crypto_libbitcoin_crypto_sse4_la_SOURCES = crypto/sha256_sse4.cpp
-
 # See explanation for -static in crypto_libbitcoin_crypto_base_la's LDFLAGS and
 # CXXFLAGS above
 crypto_libbitcoin_crypto_sse41_la_LDFLAGS = $(AM_LDFLAGS) -static