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)

TactilityKernel/include/tactility/device.h

@@ -26,6 +26,9 @@ struct DeviceType {
 
 /** Represents a piece of hardware */
 struct Device {
+    /** Device address. Can represent an index, a memory address, or some kind of offset */
+    int32_t address;
+
     /** The name of the device. Valid characters: a-z a-Z 0-9 - _ . */
     const char* name;
 
@@ -248,6 +251,13 @@ void device_for_each(void* callback_context, bool(*on_device)(struct Device* dev
  */
 void device_for_each_child(struct Device* device, void* callback_context, bool(*on_device)(struct Device* device, void* context));
 
+/**
+ * @brief Get the number of child devices.
+ * @param[in] device non-null device pointer
+ * @return the number of children
+ */
+size_t device_get_child_count(struct Device* device);
+
 /**
  * Iterate through all the known devices of a specific type
  *