util: move process.[ch] to u_process.[ch]

util: move process.[ch] to u_process.[ch]

On windows process.h is a system provided header, and it's required in
include/c11/threads_win32.h. This header interferes with searching for
that header, and results in windows build warnings with scons, but
errors in meson which doesn't allow implicit function declarations. Just
rename process to u_process, which follows the style of utils anyway.

Fixes: 2e1e6511f76370870b5cde10caa9ca3b6d0dc65f
       ("util: extract get_process_name from xmlconfig.c")
Signed-off-by: Dylan Baker <dylan.c.baker@intel.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>