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/source/drivers/display_placeholder.cpp

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: Apache-2.0
+#include <tactility/drivers/display_placeholder.h>
+#include <tactility/device.h>
+#include <tactility/driver.h>
+#include <tactility/drivers/display.h>
+#include <tactility/module.h>
+
+extern "C" {
+
+static error_t start(Device*) { return ERROR_NONE; }
+static error_t stop(Device*) { return ERROR_NONE; }
+
+extern Module root_module;
+
+Driver display_placeholder_driver = {
+    .name = "display_placeholder",
+    .compatible = (const char*[]) { "display-placeholder", nullptr },
+    .start_device = start,
+    .stop_device = stop,
+    .api = nullptr,
+    .device_type = &DISPLAY_TYPE,
+    .owner = &root_module,
+    .internal = nullptr
+};
+
+}