Add support for Watchguard Firewall X750e

See merge request !8

when running opkg update, this currently results in errors like this:

Downloading https://downloads.openwrt.org/releases/22.03-SNAPSHOT/packages/arm_cortex-a7_neon-vfpv4/base/Packages.gz
wget: SSL support not available, please install one of the libustream-.*[ssl|tls] packages as well as the ca-bundle and ca-certificates packages.
*** Failed to download the package list from https://downloads.openwrt.org/releases/22.03-SNAPSHOT/packages/arm_cortex-a7_neon-vfpv4/base/Packages.gz

since we already have wolfssl for hostapd stuff, just install
libustream-wolfssl and ca-certificates.

Build fails with it, let's see if we need it.