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/mpc/package.sh

@@ -2,6 +2,7 @@
 port=mpc
 version=1.2.1
 useconfigure=true
+use_fresh_config_sub=true
 configopts=("--target=${SERENITY_ARCH}-pc-serenity" "--with-sysroot=/")
 files="https://ftpmirror.gnu.org/gnu/mpc/mpc-${version}.tar.gz mpc-${version}.tar.gz
 https://ftpmirror.gnu.org/gnu/mpc/mpc-${version}.tar.gz.sig mpc-${version}.tar.gz.sig

Ports/mpc/patches/config.sub.patch

@@ -1,10 +0,0 @@
---- mpc-1.2.1/build-aux/config.sub	2020-10-20 17:26:31.000000000 +0100
-+++ mpc-1.2.1.serenity/build-aux/config.sub	2021-07-28 18:13:47.269493423 +0100
-@@ -1339,6 +1339,7 @@
- 	# Each alternative MUST end in a * to match a version number.
- 	# sysv* is not here because it comes later, after sysvr4.
- 	gnu* | bsd* | mach* | minix* | genix* | ultrix* | irix* \
-+	     | serenity* \
- 	     | *vms* | esix* | aix* | cnk* | sunos | sunos[34]*\
- 	     | hpux* | unos* | osf* | luna* | dgux* | auroraux* | solaris* \
- 	     | sym* | kopensolaris* | plan9* \