soc: qcom: ocmem: return -EPROBE_DEFER is ocmem is not available

soc: qcom: ocmem: return -EPROBE_DEFER is ocmem is not available

If OCMEM is declared in DT, it is expected that it is present and
handled by the driver. The GPU driver will ignore -ENODEV error, which
typically means that OCMEM isn't defined in DT. Let ocmem return
-EPROBE_DEFER if it supposed to be used, but it is not probed (yet).

Fixes: 88c1e9404f1d ("soc: qcom: add OCMEM driver")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260323-ocmem-v1-3-ad9bcae44763@oss.qualcomm.com
[bjorn: s/ERR_PTR(dev_err_probe)/dev_err_ptr_probe/
Signed-off-by: Bjorn Andersson <andersson@kernel.org>