drivers: clk: agilex: Support for enable/disable API

drivers: clk: agilex: Support for enable/disable API

Update Agilex clock driver to support enabling or disabling
the peripheral clocks via clock driver model APIs.

The caller will pass the clock ID to this driver and the driver
will then proceed to manipulate the desired bit in the Agilex clock
manager peripheral PLL register based on the given clock ID.

Signed-off-by: Alif Zakuan Yuslaimi <alif.zakuan.yuslaimi@altera.com>
Reviewed-by: Tien Fong Chee <tien.fong.chee@altera.com>