clk: starfive: Add StarFive JH7110 always-on clock driver

Add driver for the StarFive JH7110 always-on clock controller
and register an auxiliary device for always-on reset controller
which is named as "rst-aon".

Tested-by: Tommaso Merciai <tomm.merciai@gmail.com>
Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Co-developed-by: Hal Feng <hal.feng@starfivetech.com>
Signed-off-by: Hal Feng <hal.feng@starfivetech.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>