Make sure to decrement the runtime PM usage count before returning in
case regmap initialisation fails.

Fixes: 90114ca1 ("clk: qcom: add SM8550 DISPCC driver")
Cc: stable@vger.kernel.org      # 6.3
Cc: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20230718132902.21430-4-johan+linaro@kernel.orgSigned-off-by: Bjorn Andersson <andersson@kernel.org>