misc/pca955*: Move models under hw/gpio

The PCA9552 and PCA9554 devices are both I2C GPIO controllers and the
PCA9552 also can drive LEDs. Do all the necessary adjustments to move
the models under hw/gpio.

Cc: Glenn Miles <milesg@linux.vnet.ibm.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
Message-ID: <20240325134833.1484265-1-clg@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

include/hw/gpio/pca9554.h

@@ -0,0 +1,36 @@
+/*
+ * PCA9554 I/O port
+ *
+ * Copyright (c) 2023, IBM Corporation.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#ifndef PCA9554_H
+#define PCA9554_H
+
+#include "hw/i2c/i2c.h"
+#include "qom/object.h"
+
+#define TYPE_PCA9554 "pca9554"
+typedef struct PCA9554State PCA9554State;
+DECLARE_INSTANCE_CHECKER(PCA9554State, PCA9554,
+                         TYPE_PCA9554)
+
+#define PCA9554_NR_REGS 4
+#define PCA9554_PIN_COUNT 8
+
+struct PCA9554State {
+    /*< private >*/
+    I2CSlave i2c;
+    /*< public >*/
+
+    uint8_t len;
+    uint8_t pointer;
+
+    uint8_t regs[PCA9554_NR_REGS];
+    qemu_irq gpio_out[PCA9554_PIN_COUNT];
+    uint8_t ext_state[PCA9554_PIN_COUNT];
+    char *description; /* For debugging purpose only */
+};
+
+#endif