socfpga: arria10: Replace delays with busy waiting in cm_full_cfg

Using udelay while the clocks aren't fully configured causes the timer
system to save the wrong clock rate. Use sdelay and wait_on_value
instead (the values used in these functions were found experimentally).

Signed-off-by: Paweł Anikiel <pan@semihalf.com>
Reviewed-by: Tien Fong Chee <tien.fong.chee@intel.com>