framework: PAPI_DISABLE_COMPONENTS env var

This change introduces an environment variable to allow the user to
disable components at runtime.

Example Usage: export PAPI_DISABLE_COMPONENTS=rocm,rocm_smi

These changes have been tested using ROCm 7.0.2 on the Frontier
supercomputer, which contains the AMD MI250X architecture.

Signed-off-by: Daniel Barry <dbarry@vols.utk.edu>

Author: sbkathpe

src/papi.c

@@ -1049,6 +1049,16 @@ PAPI_library_init( int version )
 
 	int tmp = 0;
 
+    char *penv = getenv("PAPI_DISABLE_COMPONENTS");
+    if (penv != NULL) {
+        char *p;
+        for (p = strtok (penv, ",:"); p != NULL; p = strtok (NULL, ",:")) {
+            (void) PAPI_disable_component_by_name(p);
+        }
+    } else {
+        SUBDBG("PAPI_library_init: getenv(PAPI_DISABLE_COMPONENTS) failed.\n");
+    }
+
 	/* This is a poor attempt at a lock. 
 	   For 3.1 this should be replaced with a 
 	   true UNIX semaphore. We cannot use PAPI