wolfssl: add config flag for Curve448

This enables building WolfSSL with Curve448, which can be used by
Strongswan. This has been tested on a Linksys E8450, running OpenWrt
22.03-rc4.

This allows parity with OpenSSL, which already supports Curve448 in
OpenWrt 21.02.

Fixes openwrt/packages#18812.

Signed-off-by: Joel Low <joel@joelsplace.sg>

package/libs/wolfssl/Config.in

@@ -51,6 +51,9 @@ config WOLFSSL_HAS_ECC25519
 	bool "Include ECC Curve 25519 support"
 	default y
 
+config WOLFSSL_HAS_ECC448
+	bool "Include ECC Curve 448 support"
+
 config WOLFSSL_HAS_OPENVPN
 	bool "Include OpenVPN support"
 	default y

package/libs/wolfssl/Makefile

@@ -32,6 +32,7 @@ PKG_CONFIG_DEPENDS:=\
 	CONFIG_WOLFSSL_HAS_DH \
 	CONFIG_WOLFSSL_HAS_DTLS \
 	CONFIG_WOLFSSL_HAS_ECC25519 \
+	CONFIG_WOLFSSL_HAS_ECC448 \
 	CONFIG_WOLFSSL_HAS_OCSP \
 	CONFIG_WOLFSSL_HAS_OPENVPN CONFIG_WOLFSSL_ALT_NAMES \
 	CONFIG_WOLFSSL_HAS_SESSION_TICKET \
@@ -119,6 +120,7 @@ CONFIGURE_ARGS += \
 	--$(if $(CONFIG_WOLFSSL_HAS_SESSION_TICKET),enable,disable)-session-ticket \
 	--$(if $(CONFIG_WOLFSSL_HAS_DTLS),enable,disable)-dtls \
 	--$(if $(CONFIG_WOLFSSL_HAS_ECC25519),enable,disable)-curve25519 \
+	--$(if $(CONFIG_WOLFSSL_HAS_ECC448),enable,disable)-curve448 \
 	--$(if $(CONFIG_WOLFSSL_HAS_AFALG),enable,disable)-afalg \
 	--$(if $(CONFIG_WOLFSSL_HAS_OPENVPN),enable,disable)-openvpn \
 	--enable-devcrypto=$(if $(CONFIG_WOLFSSL_HAS_DEVCRYPTO_CBC),cbc\