cmake: apply parallel build settings to ptest tasks

ptest compile and install tasks do not have parallel build settings for
cmake. On powerful build machines this can cause overload situations
and oomkills.
Observed when building qtgrpc with ptest generally enabled in distro.

Having this in ptest class is suboptimal, but creating ptest-cmake class
just for these two variables is probably overkill.

(From OE-Core rev: 3c311fbf0c2090268e9b83123d762b05b61b4074)

(From OE-Core rev: 8270433b138284df77ed9eb21557922498663c51)

Signed-off-by: Peter Marko <peter.marko@siemens.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

meta/classes-recipe/cmake.bbclass

@@ -67,6 +67,8 @@ EXTRA_OECMAKE:append = " ${PACKAGECONFIG_CONFARGS}"
 export CMAKE_BUILD_PARALLEL_LEVEL
 CMAKE_BUILD_PARALLEL_LEVEL:task-compile = "${@oe.utils.parallel_make(d, False)}"
 CMAKE_BUILD_PARALLEL_LEVEL:task-install = "${@oe.utils.parallel_make(d, True)}"
+CMAKE_BUILD_PARALLEL_LEVEL:task-compile-ptest-base = "${@oe.utils.parallel_make(d, False)}"
+CMAKE_BUILD_PARALLEL_LEVEL:task-install-ptest-base = "${@oe.utils.parallel_make(d, True)}"
 
 OECMAKE_TARGET_COMPILE ?= "all"
 OECMAKE_TARGET_INSTALL ?= "install"