ACPI: APD: Change name from ST to FCH

AMD SoC general pupose clk is present in new platforms with
same MMIO mappings. We can reuse the same clk handler support
for other platforms. Hence, changing name from ST(SoC) to FCH(IP)

Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>