Added CONFIG_AMBIQ_COMPONENT_USE_BT and CONFIG_SOC_AMBIQ_BT_SUPPORTED
to fix empty zephyr_library() warning when BLE is not needed for compile.
Added CMake message if BT related Ambiq specific Kconfig is overriden for
not supported SoC.
Signed-off-by: Swift Tian <swift.tian@ambiq.com>