feat(tools/cbmc): add option to test a single testbench

This feature becomes useful when working on a single testbench. There is
no need to wait for the other testbenches to finish analysis.

Change-Id: I277b37ef796c66c26c03c4b3ca2cd29c705cfc88
Signed-off-by: Mate Toth-Pal <mate.toth-pal@arm.com>
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index de0e8cc..805482b 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -282,6 +282,7 @@
    RMM_COVERAGE 		,ON | OFF		,OFF			,"Enable coverage analysis"
    RMM_HTML_COV_REPORT		,ON | OFF		,ON			,"Enable HTML output report for coverage analysis"
    RMM_CBMC_VIEWER_OUTPUT	,ON | OFF		,OFF			,"Generate report of CBMC results using the tool cbmc-viewer"
+   RMM_CBMC_SINGLE_TESTBENCH	,			,OFF			,"Run CBMC on a single testbench instead on all of them"
 
 .. _llvm_build: