clk: qcom: dispcc-sm8750: Allow dumping regmap

Reading few registers at the end of the block (e.g. 0x10000, 0x10004)
results in synchronous external abort, so limit the regmap to the last
readable register which allows dumping the regs for debugging.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20250212163243.237658-1-krzysztof.kozlowski@linaro.org


Signed-off-by: Bjorn Andersson <andersson@kernel.org>