dt-bindings: nvmem: qfprom: Add compatible for QCS615

Document compatible for QFPROM used on QCS615. It's compatible
with generic QFPROM fallback.

Signed-off-by: Lijuan Gao <quic_lijuang@quicinc.com>
Link: https://lore.kernel.org/all/20240912-add_qfprom_compatible_for_qcs615-v1-1-9ef2e26c14ee@quicinc.com/


Signed-off-by: Rob Herring (Arm) <robh@kernel.org>