spi: dt-bindings: aspeed,ast2600-fmc: Add AST2700 SoC support

spi: dt-bindings: aspeed,ast2600-fmc: Add AST2700 SoC support

Add AST2700 to the list of supported SoCs in the ASPEED FMC/SPI bindings.
AST2700 FMC/SPI controllers are not compatible with AST2600 due to the
following hardware differences:

- Address decoding unit uses 64KB granularity (AST2600 uses 1MB).
- Segment register semantics are changed.
    AST2600: start <= range <= end
    AST2700: start <= range < end
- Hardware limitations in AST2600 address decoding registers have been
  resolved in AST2700, so extra callback function used for bug fixup
  is no longer required.

These differences require distinct compatible strings for AST2700.

Signed-off-by: Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20251114101042.1520997-2-chin-ting_kuo@aspeedtech.com
Signed-off-by: Mark Brown <broonie@kernel.org>