selftests/nolibc: make sure gcc always use little endian on MIPS

The test on MIPS stopped working after I upgraded some of my toolchains
to use the ones from kernel.org because the mips toolchain defaults to
big endian, even though it supports both endians. Let's just add an
explicit -EL to make sure it always succeeds like the kernel does.
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/testing/selftests/nolibc/Makefile

@@ -77,6 +77,7 @@ Q=@
 endif
 
 CFLAGS_s390 = -m64
+CFLAGS_mips = -EL
 CFLAGS_STACKPROTECTOR ?= $(call cc-option,-mstack-protector-guard=global $(call cc-option,-fstack-protector-all))
 CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables -std=c89 \
 		$(call cc-option,-fno-stack-protector) \