dt-bindings: sram: qcom,imem: document qdu1000

Add compatible for QDU1000 and QRU1000 SoCs IMEM.

Signed-off-by: Komal Bajaj <quic_kbajaj@quicinc.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230522151206.22654-2-quic_kbajaj@quicinc.com