Please update config.guess to support riscv64

[FantasqueX]

Hi, I'm building packages for ArchLinux RISCV. When building most package executing ./configure, an error occurred.

checking build system type... autoconf/config.guess: unable to guess system type

This script, last modified 2012-02-10, has failed to recognize
the operating system you are using. It is advised that you
download the most up to date version of the config scripts from

  http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess;hb=HEAD
and
  http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub;hb=HEAD

If the version you run (autoconf/config.guess) is already up to date, please
send the following data and any information you think might be
pertinent to <[email protected]> in order to provide the needed
information to handle your system.

config.guess timestamp = 2012-02-10

uname -m = riscv64
uname -r = 5.18.3-arch1-1
uname -s = Linux
uname -v = #1 SMP PREEMPT Sun, 12 Jun 2022 18:42:25 +0000

/usr/bin/uname -p = unknown
/bin/uname -X     = 

hostinfo               = 
/bin/universe          = 
/usr/bin/arch -k       = 
/bin/arch              = 
/usr/bin/oslevel       = 
/usr/convex/getsysinfo = 

UNAME_MACHINE = riscv64
UNAME_RELEASE = 5.18.3-arch1-1
UNAME_SYSTEM  = Linux
UNAME_VERSION = #1 SMP PREEMPT Sun, 12 Jun 2022 18:42:25 +0000
configure: error: cannot guess build type; you must specify one

This is an issue because config,guess and config.sub are outdated. More recent version of them can recognize RISCV64 properly.