Driver improvements (#535)

- New drivers:
  - SD SPI
  - spi_peripheral
  - touch_placeholder
  - display_placeholder
- Devicetree compiler:
  - Implement phandle-arrays
  - Implement device addresses
- Add placeholder drivers to all devices with a SPI display
- SPI driver: add `cs-pins` and set them to high on driver start
- FileSystem: add `file_system_set_owner()` and `file_system_get_owner()`
- File locking is now checking if the related `FileSystem` is part of a shared SPI bus
- Add `device_get_child_count()`
- SDMMC driver: Remove default of `slot` value
- Fix for Crowpanel Basic 3.5" display (add delay to booting)
- Fix for LilyGO T-HMI SD card mounting (delayed mounting by disabling it initially in the dts)

Platforms/platform-esp32/bindings/espressif,esp32-uart.yaml

@@ -12,18 +12,18 @@ properties:
       The port number, defined by uart_port_t.
       Depending on the hardware, these values are available: UART_NUM_0, UART_NUM_1, UART_NUM_2
   pin-tx:
-    type: phandle-array
+    type: phandles
     required: true
     description: TX pin
   pin-rx:
-    type: phandle-array
+    type: phandles
     required: true
     description: RX pin
   pin-cts:
-    type: phandle-array
+    type: phandles
     default: GPIO_PIN_SPEC_NONE
     description: CTS pin
   pin-rts:
-    type: phandle-array
+    type: phandles
     default: GPIO_PIN_SPEC_NONE
     description: RTS pin