clk: qcom: gdsc: Support new GPU GDSC enable/disable sequence

While enabling or disabling the graphics GDSC on some devices,
the GX_DOMAIN_MISC register needs to be accessed as a new
requirement. Add support to load the new register address and
to access the GX_GMEM_CLAMP_IO bit before touching the actual
GX_GDSCR register to enable/disable the GDSC.

Signed-off-by: Deepak Katragadda <dkatraga@codeaurora.org>
Change-Id: I3005a495f1fbc66e53af00bc43e44acc4429e50e