Merge develop into main (#303)

- `DisplayDevice` improvements related `DisplayDriver`
- Replaced incorrect usage of `spiBusHandle` with `spiHostDevice` in all SPI display devices
- Disabled `DisplayDriver` support for RGB displays for now
- Updated `GraphicsDemo` project for the above changes
- TactilityC improvements:
  - created `tt_hal_device_find()`
  - created `tt_hal_display_*`
  - created `tt_hal_touch_*`
  - created `tt_lvgl_*`
  - export `tt_app_*` calls

TactilityC/Include/tt_kernel.h

@@ -0,0 +1,50 @@
+#pragma once
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef unsigned long TickType;
+
+/**
+ * Stall the current task for the specified amount of time.
+ * @param milliseconds the time in milliseconds to stall.
+ */
+void tt_kernel_delay_millis(uint32_t milliseconds);
+
+/**
+ * Stall the current task for the specified amount of time.
+ * @param milliseconds the time in microsends to stall.
+ */
+void tt_kernel_delay_micros(uint32_t microSeconds);
+
+/**
+ * Stall the current task for the specified amount of time.
+ * @param milliseconds the time in ticks to stall.
+ */
+void tt_kernel_delay_ticks(TickType ticks);
+
+/** @return the number of ticks since the device was started */
+TickType tt_kernel_get_ticks();
+
+/** Convert milliseconds to ticks */
+TickType tt_kernel_millis_to_ticks(uint32_t milliSeconds);
+
+/** Stall the current task until the specified timestamp
+ * @return false if for some reason the delay was broken off
+ */
+bool tt_kernel_delay_until_tick(TickType tick);
+
+/** @return the tick frequency of the kernel (commonly 1000 Hz when running FreeRTOS) */
+uint32_t tt_kernel_get_tick_frequency();
+
+/** @return the number of milliseconds that have passed since the device was started */
+uint32_t tt_kernel_get_millis();
+
+unsigned long tt_kernel_get_micros();
+
+#ifdef __cplusplus
+}
+#endif