clk: qcom: gpucc-lito: configure gpu_cc_ahb_clk to be always-on

Add the CLK_IS_CRITICAL flag for gpu_cc_ahb_clk to keep it
enabled at all times. This is needed to avoid unclocked
register accesses by SMMU since SMMU vote registers do not
enable gpu_cc_ahb_clk.
Also skip an enable check for this clock since it will not
be physically enabled until gpu_cx_gdsc is enabled.

Change-Id: I8dff7012c0f9bd1bcce51da80673974ffd095764
Signed-off-by: Taniya Das <tdas@codeaurora.org>