ARM: compile everything with relro / bind_now.

Enable relro / bind_now when compiling Android applications.
This marks certain regions of memory as read-only after linking,
making memory corruption security vulnerabilities are harder
to exploit.

See:
 * http://www.akkadia.org/drepper/nonselsec.pdf (section 6)
 * http://tk-blog.blogspot.com/2009/02/relro-not-so-well-known-memory.html

Stop using the custom linker script, which inhibits
relro / bind_now support.

Change-Id: Ie97ccdd2845886bbc2ba2fdd47eed0ff4b29b60b
diff --git a/core/combo/TARGET_linux-arm.mk b/core/combo/TARGET_linux-arm.mk
index ca12ba2..4a461f8 100644
--- a/core/combo/TARGET_linux-arm.mk
+++ b/core/combo/TARGET_linux-arm.mk
@@ -135,6 +135,8 @@
 
 TARGET_GLOBAL_LDFLAGS += \
 			-Wl,-z,noexecstack \
+			-Wl,-z,relro \
+			-Wl,-z,now \
 			-Wl,--icf=safe \
 			$(arch_variant_ldflags)
 
@@ -246,7 +248,7 @@
 
 define transform-o-to-shared-lib-inner
 $(hide) $(PRIVATE_CXX) \
-	-nostdlib -Wl,-soname,$(notdir $@) -Wl,-T,$(BUILD_SYSTEM)/armelf.xsc \
+	-nostdlib -Wl,-soname,$(notdir $@) \
 	-Wl,--gc-sections \
 	-Wl,-shared,-Bsymbolic \
 	$(PRIVATE_TARGET_GLOBAL_LD_DIRS) \