Separate flags from commands in HOST_CONFIGURE_OPTS

Just as we did for LD/LDFLAGS, pass CFLAGS and CXXFLAGS in their own
variables.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/Makefile.in

@@ -225,10 +225,12 @@ HOST_CONFIGURE_OPTS=PATH=$(HOST_PATH) \
 		AS="$(HOSTAS)" \
 		LD="$(HOSTLD)" \
 		NM="$(HOSTNM)" \
-		CC="$(HOSTCC) $(HOST_CFLAGS)" \
-		GCC="$(HOSTCC) $(HOST_CFLAGS)" \
-		CXX="$(HOSTCXX) $(HOST_CXXFLAGS)" \
-		CPP="$(HOSTCPP) $(HOST_CFLAGS)" \
+		CC="$(HOSTCC)" \
+		GCC="$(HOSTCC)" \
+		CXX="$(HOSTCXX)" \
+		CPP="$(HOSTCPP)" \
+		CFLAGS="$(HOST_CFLAGS)" \
+		CXXFLAGS="$(HOST_CXXFLAGS)" \
 		LDFLAGS="$(HOST_LDFLAGS)" \
 		PKG_CONFIG_ALLOW_SYSTEM_CFLAGS=1 \
 		PKG_CONFIG_ALLOW_SYSTEM_LIBS=1 \