CMake: set CMAKE_MODULE_PATH in the Mbed OS CMakelists.txt ...

Update CMAKE_MODULE_PATH at once place.

Note, we update also CMAKE_MODULE_PATH in app.cmake. This is temporary until we get a proper way to include
Mbed Os (removing app.cmake need to be included by an application).

CMake targets: remove MBED_PATH, use stadard variables ...

- list files included via module path
- <project-name>_SOURCE_DIR for sources that are out of the current processed CMake
- CMAKE_CURRENT_LIST_DIR for listfiles

CMake: Refactor Cypress targets ...

Refactor all Cypress targets to be CMake buildsystem targets. This removes
the need for checking MBED_TARGET_LABELS repeatedly and allows us to be
more flexible in the way we include MBED_TARGET source in the build.

A side effect of this is it will allow us to support custom targets
without breaking the build for 'standard' targets, as we use CMake's
standard mechanism for adding build rules to the build system, rather
than implementing our own layer of logic to exclude files not needed for
the target being built. Using this approach, if an MBED_TARGET is not
linked to using target_link_libraries its source files will not be
added to the build. This means custom target source can be added to the
user's application CMakeLists.txt without polluting the build system
when trying to compile for a standard MBED_TARGET.

CMake: Add support for CY8CKIT064B0S2_4343W