openssl: support building the binary without MMU

The commit 720893b62510438237b9923d744dd079ddb4f67d "openssl: disable
apps for NOMMU" prevented the openssl binary from being built without
MMU in order to fix a build failure without fork(). However, openssl is
designed to support the lack of fork() with -DHAVE_FORK=0, so allow the
openssl binary to be enabled without MMU thanks to this option.

Signed-off-by: Benoît Thébaudeau <benoit@wsystem.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/openssl/Config.in

@@ -13,15 +13,12 @@ if BR2_PACKAGE_OPENSSL
 
 config BR2_PACKAGE_OPENSSL_BIN
 	bool "openssl binary"
-	# uses fork()
-	depends on BR2_USE_MMU
 	depends on !BR2_STATIC_LIBS
 	help
 	  Install the openssl binary to the target file system. This is a
 	  command line tool for doing various crypthographic stuff.
 
 comment "openssl binary needs a toolchain w/ dynamic library"
-	depends on BR2_USE_MMU
 	depends on BR2_STATIC_LIBS
 
 config BR2_PACKAGE_OPENSSL_ENGINES

package/openssl/openssl.mk

@@ -22,6 +22,10 @@ endef
 OPENSSL_PRE_CONFIGURE_HOOKS += OPENSSL_DISABLE_APPS
 endif
 
+ifeq ($(BR2_USE_MMU),)
+OPENSSL_CFLAGS += -DHAVE_FORK=0
+endif
+
 ifeq ($(BR2_PACKAGE_CRYPTODEV_LINUX),y)
 OPENSSL_CFLAGS += -DHAVE_CRYPTODEV -DUSE_CRYPTODEV_DIGESTS
 OPENSSL_DEPENDENCIES += cryptodev-linux