Initial commit: Set up Zephyr MQTT project

boards/esp32c6_devkitc_esp32c6_hpcore.overkay

@@ -0,0 +1,5 @@
+&flash0 {
+    reg = <0x0 0x400000>; /* 4MB flash */
+};
+
+#include "espressif/partitions_0x0_default_4M.dtsi"

boards/native_sim.conf

@@ -0,0 +1,4 @@
+CONFIG_FLASH_SIMULATOR=y
+
+# Disable native logging backends so we don't get conflicts with the shell if we start it with --uart_stdinout
+CONFIG_LOG_BACKEND_NATIVE_POSIX=n

boards/native_sim.overlay

@@ -0,0 +1,13 @@
+/ {
+	switches {
+		compatible = "gpio-keys";
+		sw0: switch_0 {
+			label = "User switch";
+			gpios = <&gpio0 11 GPIO_ACTIVE_LOW>;
+		};
+	};
+
+	aliases {
+		switch0 = &sw0;
+	};
+};