coresight: tmc: Move ACPI device support from AMBA to platform driver

This drops tmc (etr, etf & etb) from the AMBA ACPI device list and instead
moves them inside platform ACPI devices list which can be detected, and
processed via a new platform driver i.e tmc_platform_driver.

Platform driver's probe() function initializes the required clock support.
A new clock element has been added to struct tmc_drvdata in this regard.
A new helper __tmc_probe() which has been refactored from tmc_probe(),
which now can be used from both AMBA and platfrom driver probe functions.
Similarly __tmc_remvoe() has also been refactored from tmc_remove() to be
in both place. The platform driver also adds power management operations
support.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>