This fixes a few issues on the Agilex clock configuration:
- Set clock manager into boot mode before configuring clock
- Fix wrong divisor used when calculating vcocalib
- PLL sync configuration should be read and then written
- Wait PLL lock after PLL sync configuration is done
- Clear interrupt bits instead of set interrupt bits after configuration

Signed-off-by: Tien Hock Loh <tien.hock.loh@intel.com>
Change-Id: I54c1dc5fe9b102e3bbc1237a92d8471173b8af70