clk: sophgo: Add clock support for SG2000 SoC

Add init code for SG2000 SoC.

Signed-off-by: Inochi Amaoto <inochiama@outlook.com>
Link: https://github.com/sophgo/sophgo-doc/releases/tag/sg2000-datasheet-v1.0-alpha
Link: https://lore.kernel.org/r/IA1PR20MB49537156E71B64483F15C0F2BB262@IA1PR20MB4953.namprd20.prod.outlook.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>