vlock: add dynamic switch from pll to enc mdoe

vlock: add dynamic switch from pll to enc mdoe

PD#169634: vlock: add dynamic switch from pll to enc mode

1.seperate vlock process from amvecm_on_vs,
avoid the influence of repeate call.
2.add dynamic switch from pll to enc mode,
pll adj firstly,then switch to enc mode do fine tuning.
3.seperate vlock reg init from amcm interface,
avoid the influence of rdma mode.
4.decrease enc line adjust limit.
5.add enc adjust range check.

Change-Id: I6352b45e9ec8869be43660c03352d1a406ca8a0a
Signed-off-by: Dezhi Kong <dezhi.kong@amlogic.com>