[nvptx] Add nvptx-sm.def

[nvptx] Add nvptx-sm.def

Add a file gcc/config/nvptx/nvptx-sm.def that lists all sm_xx versions used in
the port, like so:
...
NVPTX_SM(30, NVPTX_SM_SEP)
NVPTX_SM(35, NVPTX_SM_SEP)
NVPTX_SM(53, NVPTX_SM_SEP)
NVPTX_SM(70, NVPTX_SM_SEP)
NVPTX_SM(75, NVPTX_SM_SEP)
NVPTX_SM(80,)
...
and use it in various places using a pattern:
...
  #define NVPTX_SM(XX, SEP) { ... }
  #include "nvptx-sm.def"
  #undef NVPTX_SM
...

Tested on nvptx.

gcc/ChangeLog:

2022-02-25  Tom de Vries  <tdevries@suse.de>

	* config/nvptx/nvptx-sm.def: New file.
	* config/nvptx/nvptx-c.cc (nvptx_cpu_cpp_builtins): Use nvptx-sm.def.
	* config/nvptx/nvptx-opts.h (enum ptx_isa): Same.
	* config/nvptx/nvptx.cc (sm_version_to_string)
	(nvptx_omp_device_kind_arch_isa): Same.