build: add DebugCoverage build type

Add a new build type to capture compiler flags settings needed for GCOV
based coverage measurement. This build type is only supported by
environments targeting Linux.
The aim is to allow extending coverage measurement to sub-builds
(especially libts).

Signed-off-by: Gyorgy Szing <gyorgy.szing@arm.com>
Change-Id: I1de619c0b96c1d2d519432458c3eac4aed947acf
diff --git a/deployments/deployment.cmake b/deployments/deployment.cmake
index 76b0f18..b098c7c 100644
--- a/deployments/deployment.cmake
+++ b/deployments/deployment.cmake
@@ -63,7 +63,7 @@
 endif()
 
 # List of supported build types. Needs to be in alignment with the toolchain file
-set(TS_SUPPORTED_BUILD_TYPES DEBUG "MINSIZEREL" "MINSIZWITHDEBINFO" "RELEASE" "RELWITHDEBINFO" CACHE
+set(TS_SUPPORTED_BUILD_TYPES "DEBUG" "MINSIZEREL" "MINSIZWITHDEBINFO" "RELEASE" "RELWITHDEBINFO" "DEBUGCOVERAGE" CACHE
   STRING "List of supported build types.")
 
 # Convert the build type string to upper case to help case insensitive comparison.