fix libphidget22 build on riscv64

[sihuan]

The config.guess in the lib is too old to recognise the riscv64 architecture and I get the following error:

[  636s] information to handle your system.
[  636s] 
[  636s] config.guess timestamp = 2013-06-10
[  636s] 
[  636s] uname -m = riscv64
[  636s] uname -r = 5.10.0-153.1.0.80.oe2203.riscv64
[  636s] uname -s = Linux
[  636s] uname -v = #1 SMP Mon Mar 23 19:10:41 UTC 2020
[  636s] 
[  636s] /usr/bin/uname -p = riscv64
[  636s] /bin/uname -X     = 
[  636s] 
[  636s] hostinfo               = 
[  636s] /bin/universe          = 
[  636s] /usr/bin/arch -k       = 
[  636s] /bin/arch              = riscv64
[  636s] /usr/bin/oslevel       = 
[  636s] /usr/convex/getsysinfo = 
[  636s] 
[  636s] UNAME_MACHINE = riscv64
[  636s] UNAME_RELEASE = 5.10.0-153.1.0.80.oe2203.riscv64
[  636s] UNAME_SYSTEM  = Linux
[  636s] UNAME_VERSION = #1 SMP Mon Mar 23 19:10:41 UTC 2020
[  636s] configure: error: cannot guess build type; you must specify one

This patch can update config.guess and config.sub and build successfully on riscv64 machines.