gcc-8: Disable libssp for non mingw targets

(From OE-Core rev: 2c5d24c92b5bd6855e808ff67ab4f51aaa95923a)

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/gcc/gcc-8.1.inc

@@ -87,10 +87,12 @@ FORTRAN = ""
 JAVA = ""
 
 LTO = "--enable-lto"
+SSP ?= "--disable-libssp"
+SSP_mingw32 = "--enable-libssp"
 
 EXTRA_OECONF_BASE = "\
     ${LTO} \
-    --enable-libssp \
+    ${SSP} \
     --enable-libitm \
     --disable-bootstrap \
     --disable-libmudflap \
@@ -114,7 +116,7 @@ EXTRA_OECONF_INITIAL = "\
     --disable-plugin \
     --enable-decimal-float=no \
     --without-isl \
-    gcc_cv_libc_provides_ssp=yes \
+    --disable-libssp \
 "
 
 EXTRA_OECONF_PATHS = "\