* CMake version requirement bumped up to 3.21.0
   * CMake 3.22.4 installed in the local Python virtualenv
 * CPU flags updated in toolchain files.
 * Using __ARM_FEATURE_DSP instead of potentially defining
   ARM_MATH_DSP wrongly.
 * CMake project version bumped up to 22.05.0

Changes also made for MLECO-3107 (pack generation):

 * TensorFlow Lite Micro CMSIS-pack version updated to
   1.22.02.
 * Change to using __ARM_FEATURE_DSP will also help the
   generated pack.

Partial changes for MLECO-3095:

 * CMSIS updated to version post 5.9.0
 * TensorFlow Lite Micro updated to latest available
 * Ethos-U driver and core-platform repositories updated
   to 20.05_rc2 tags.

Change-Id: I012c9e65897aed8ce589cff9bfe3a19efc3edeb9
Signed-off-by: Kshitij Sisodia <kshitij.sisodia@arm.com>