hwspinlock: qcom: correct MMIO max register for newer SoCs

Newer ARMv8 Qualcomm SoCs using 0x1000 register stride have maximum
register 0x20000 (32 mutexes * 0x1000).

Fixes: 7a1e6fb1

 ("hwspinlock: qcom: Allow mmio usage in addition to syscon")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220909092035.223915-4-krzysztof.kozlowski@linaro.org