hw/misc: Rename axp209 to axp22x and add support AXP221 PMU

This patch adds minimal support for AXP-221 PMU and connect it to
bananapi M2U board.

Signed-off-by: qianfan Zhao <qianfanguijin@163.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
7 files changed