tzcode-native: Set cc to ${CC}

Building on a system without "cc" showed this recipe doesn't respect
the $CC variable. Fix this by passing the right option to the makefile.

(From OE-Core rev: 402080c0a77443f541fa3d658b79f3fba327279d)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-extended/tzcode/tzcode-native_2017a.bb

@@ -18,6 +18,8 @@ S = "${WORKDIR}"
 
 inherit native
 
+EXTRA_OEMAKE += "cc=${CC}"
+
 do_install () {
         install -d ${D}${bindir}/
         install -m 755 zic ${D}${bindir}/