Add USB host header; remove hal_gpio headers

Add lib-gd32/include/device/host/host.h which introduces a usb::host API with Status, Speed and Class enums and declarations for get_status(), get_speed() and get_class(). Remove two legacy GPIO headers: lib-hal/include/gd32/hal_gpio.h and lib-hal/include/hal_gpio.h (deleted), likely as part of HAL refactoring or header consolidation.

Author: vanvught

lib-gd32/include/device/host/host.h

@@ -0,0 +1,43 @@
+/*
+ * host.h
+ */
+
+#ifndef DEVICE_USB_HOSTMSC_H_
+#define DEVICE_USB_HOSTMSC_H_
+
+
+namespace usb::host {
+
+enum class Status {
+	NOT_AVAILABLE,
+	DISCONNECTED,
+	RESET,
+	SPEED_AVAILALBE,
+	ATTACHED,
+	CONNECTED,
+	ENUMERATION_COMPLETED,
+	READY,
+	DEVICE_NOT_SUPPORTED,
+	UNRECOVERABLE_ERROR
+};
+
+enum class Speed {
+	FAULT,
+	LOW,
+	FULL,
+	HIGH
+};
+
+enum class Class {
+	NOT_SUPPORTED,
+	MSC,
+	HID
+};
+
+Status get_status();
+Speed get_speed();
+Class get_class();
+} // namespace usb::host
+
+
+#endif /* DEVICE_USB_HOSTMSC_H_ */