feat(cbmc): add host target for CBMC

Change-Id: Id7d043b691aa3f70f4c1c161360c276bc7eb50b1
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 9c525d7..985fc6b 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -271,7 +271,7 @@
    MBEDTLS_ECP_MAX_OPS		,248 -			,1000			,"Number of max operations per ECC signing iteration"
    RMM_FPU_USE_AT_REL2		,ON | OFF		,OFF(fake_host) ON(aarch64),"Enable FPU/SIMD usage in RMM."
    RMM_MAX_GRANULES		,			,0			,"Maximum number of memory granules available to the system"
-   HOST_VARIANT			,host_build | host_test	,host_build		,"Variant to build for the host platform. Only available when RMM_PLATFORM=host"
+   HOST_VARIANT			,host_build | host_test | host_cbmc	,host_build	,"Variant to build for the host platform. Only available when RMM_PLATFORM=host"
    HOST_MEM_SIZE		,			,0x40000000		,"Host memory size that will be used as physical granules"
    RMM_COVERAGE 		,ON | OFF		,OFF			,"Enable coverage analysis"
    RMM_HTML_COV_REPORT		,ON | OFF		,ON			,"Enable HTML output report for coverage analysis"