clk: qcom: gdsc: Add support to configure en_few/rest wait values

The EN_FEW_WAIT and EN_REST_WAIT bits value may differ from the
default value of 0x2. Allow the value to be taken as input from
device tree as parameter 'qcom,en-few-wait-val' and
'qcom,en-rest-wait-val'.

Change-Id: I319c8cf5322713e2cb00c9e662084ec6b930b6a7
Signed-off-by: Amit Nischal <anischal@codeaurora.org>