boot/optee-os: Add support to build with host-cmake

Some specific versions of OP-TEE need cmake on the host to build the scmi
firmware, like the newly release STMicroelectronics 3.19.0-stm32mp-r2
version.

To allow building such OP-TEE OS versions, this commit adds the option
BR2_TARGET_OPTEE_OS_NEEDS_CMAKE which when enabled ensures that host-cmake
is built before OP-TEE OS.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
[Arnout: use BR2_CMAKE_HOST_DEPENDENCY]
Signed-off-by: Arnout Vandecappelle <arnout@mind.be>

boot/optee-os/Config.in

@@ -91,6 +91,12 @@ config BR2_TARGET_OPTEE_OS_NEEDS_PYTHON_CRYPTOGRAPHY
 	  python-cryptography. Select this option if optee-os needs
 	  python-cryptography to be built.
 
+config BR2_TARGET_OPTEE_OS_NEEDS_CMAKE
+	bool "OP-TEE OS needs cmake"
+	help
+	  Select this option if your OP-TEE OS platform configuration
+	  requires the cmake build system to be available.
+
 config BR2_TARGET_OPTEE_OS_CORE
 	bool "Build core"
 	default y

boot/optee-os/optee-os.mk

@@ -30,6 +30,10 @@ endif
 
 OPTEE_OS_DEPENDENCIES = host-openssl host-python3 host-python-pyelftools
 
+ifeq ($(BR2_TARGET_OPTEE_OS_NEEDS_CMAKE),y)
+OPTEE_OS_DEPENDENCIES += $(BR2_CMAKE_HOST_DEPENDENCY)
+endif
+
 ifeq ($(BR2_TARGET_OPTEE_OS_NEEDS_PYTHON_CRYPTOGRAPHY),y)
 OPTEE_OS_DEPENDENCIES += host-python-cryptography
 else