fix(llcc68): align spi binding with zephyr

Add a module-local .gitignore entry for macOS .DS_Store artifacts so generated Finder metadata does not dirty the submodule.

Declare the SPI chip-select delay binding properties as integers so Zephyr devicetree validation accepts the custom LLCC68 binding.

Pass the configured setup delay into SPI_DT_SPEC_INST_GET using the Zephyr 4 three-argument API, converting the nanosecond devicetree value to the microsecond spi_cs_control delay field.

dts/bindings/semtech,llcc68-weihua.yaml

@@ -71,7 +71,9 @@ properties:
       which the driver holds active. This mode must not use tx-enable-gpios.
 
   spi-cs-setup-delay-ns:
+    type: int
     default: 100000
 
   spi-cs-hold-delay-ns:
+    type: int
     default: 100000