Ports: Remove some config.sub patches and download a fresh one if needed

All of these patches did the same thing, which is already in upstream
config.sub.
With this change, we need only add `use_fresh_config_sub=true` to
the package.sh file.
Note that this is not done automatically in case the port has a modified
config.sub file.

Ports/libffi/package.sh

@@ -2,5 +2,6 @@
 port=libffi
 version=3.4.2
 useconfigure=true
+use_fresh_config_sub=true
 files="https://github.com/libffi/libffi/releases/download/v${version}/libffi-${version}.tar.gz libffi-${version}.tar.gz 540fb721619a6aba3bdeef7d940d8e9e0e6d2c193595bc243241b77ff9e93620"
 auth_type=sha256

Ports/libffi/patches/fix-autoconf.patch

@@ -1,13 +0,0 @@
-diff --git a/config.sub b/config.sub
-index 14b5150..b541768 100644
---- a/config.sub
-+++ b/config.sub
-@@ -1722,7 +1722,7 @@ case $os in
- 	     | skyos* | haiku* | rdos* | toppers* | drops* | es* \
- 	     | onefs* | tirtos* | phoenix* | fuchsia* | redox* | bme* \
- 	     | midnightbsd* | amdhsa* | unleashed* | emscripten* | wasi* \
--	     | nsk* | powerunix* | genode* | zvmoe* )
-+	     | nsk* | powerunix* | genode* | zvmoe* | serenity* )
- 		;;
- 	# This one is extra strict with allowed versions
- 	sco3.2v2 | sco3.2v[4-9]* | sco5v6*)