dt-bindings: memory: factorise LPDDR channel binding into SDRAM channel

dt-bindings: memory: factorise LPDDR channel binding into SDRAM channel

LPDDR, DDR and so SDRAM channels exist and share the same properties, they
have a compatible, ranks, and an io-width.

Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Clément Le Goffic <legoffic.clement@gmail.com>
Link: https://patch.msgid.link/20251118-b4-ddr-bindings-v9-3-a033ac5144da@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>