fedora-disk-base: remove @arm-tools and bcm283x-firmware

On riscv64 Koji we don't have aarch64 configured. Somehow that's causing
an issue with anaconda installs for riscv64:

```
         Some packages, groups or modules are missing.

         Problems in request:
         missing packages: bcm283x-firmware
         missing groups or modules: @arm-tools
```

Signed-off-by: David Abdurachmanov <davidlt@rivosinc.com>

fedora-disk-base.ks

@@ -38,9 +38,9 @@ kernel
 dracut-config-generic
 -dracut-config-rescue
 # install tools needed to manage and boot arm systems
-@arm-tools
+#@arm-tools
 chrony
-bcm283x-firmware
+#bcm283x-firmware
 initial-setup
 # Intel wireless firmware assumed never of use for disk images
 -iwl*