perf/amlogic: Add support for Amlogic meson G12 SoC DDR PMU driver

Add support for Amlogic Meson G12 Series SOC - DDR bandwidth PMU driver
framework and interfaces. The PMU can not only monitor the total DDR
bandwidth, but also individual IP module bandwidth.

Signed-off-by: Jiucheng Xu <jiucheng.xu@amlogic.com>
Tested-by: Chris Healy <healych@amazon.com>
Link: https://lore.kernel.org/r/20221121021602.3306998-1-jiucheng.xu@amlogic.com
Signed-off-by: Will Deacon <will@kernel.org>