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)

Devices/m5stack-core2/m5stack,core2.dts

@@ -9,6 +9,8 @@
 #include <tactility/bindings/esp32_uart.h>
 #include <bindings/mpu6886.h>
 #include <bindings/bm8563.h>
+#include <tactility/bindings/esp32_sdspi.h>
+#include <tactility/bindings/display_placeholder.h>
 
 // Reference: https://docs.m5stack.com/en/core/Core2
 / {
@@ -51,9 +53,21 @@
 	spi0 {
 		compatible = "espressif,esp32-spi";
 		host = <SPI2_HOST>;
+		cs-gpios = <&gpio0 5 GPIO_FLAG_NONE>, // Display
+				   <&gpio0 4 GPIO_FLAG_NONE>; // SD card
 		pin-mosi = <&gpio0 23 GPIO_FLAG_NONE>;
 		pin-miso = <&gpio0 38 GPIO_FLAG_NONE>;
 		pin-sclk = <&gpio0 18 GPIO_FLAG_NONE>;
+	
+		display@0 {
+			compatible = "display-placeholder";
+		};
+
+		sdcard@1 {
+			compatible = "espressif,esp32-sdspi";
+			status = "disabled"; // Must be started after display
+			frequency-khz = <20000>;
+		};
 	};
 
 	// NS4168: Speaker and microphone