valgrind: enable tls support

Tested with example program from [1] with qemu_x86_64.

[1] http://valgrind.10908.n7.nabble.com/Thread-local-storage-TLS-support-td40815.html

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/valgrind/valgrind.mk

@@ -9,9 +9,15 @@ VALGRIND_SITE = http://valgrind.org/downloads
 VALGRIND_SOURCE = valgrind-$(VALGRIND_VERSION).tar.bz2
 VALGRIND_LICENSE = GPLv2 GFDLv1.2
 VALGRIND_LICENSE_FILES = COPYING COPYING.DOCS
-VALGRIND_CONF_OPTS = --disable-tls --disable-ubsan
+VALGRIND_CONF_OPTS = --disable-ubsan
 VALGRIND_INSTALL_STAGING = YES
 
+ifeq ($(BR2_GCC_ENABLE_TLS),y)
+VALGRIND_CONF_OPTS += --enable-tls
+else
+VALGRIND_CONF_OPTS += --disable-tls
+endif
+
 # When Valgrind detects a 32-bit MIPS architecture, it forcibly adds
 # -march=mips32 to CFLAGS; when it detects a 64-bit MIPS architecture,
 # it forcibly adds -march=mips64. This causes Valgrind to be built