hw/watchdog/wdt_aspeed: Extend MMIO range to cover more registers

hw/watchdog/wdt_aspeed: Extend MMIO range to cover more registers

When booting the Zephyr demo in [1] we get:

  aspeed.io: unimplemented device write (size 4, offset 0x185128, value 0x030f1ff1) <--
  aspeed.io: unimplemented device write (size 4, offset 0x18512c, value 0x03fffff1)

This corresponds to this Zephyr code [2]:

  static int aspeed_wdt_init(const struct device *dev)
  {
    const struct aspeed_wdt_config *config = dev->config;
    struct aspeed_wdt_data *const data = dev->data;
    uint32_t reg_val;

    /* disable WDT by default */
    reg_val = sys_read32(config->ctrl_base + WDT_CTRL_REG);
    reg_val &= ~WDT_CTRL_ENABLE;
    sys_write32(reg_val, config->ctrl_base + WDT_CTRL_REG);

    sys_write32(data->rst_mask1,
                config->ctrl_base + WDT_SW_RESET_MASK1_REG);   <------
    sys_write32(data->rst_mask2,
                config->ctrl_base + WDT_SW_RESET_MASK2_REG);

    return 0;
  }

The register definitions are [3]:

  #define WDT_RELOAD_VAL_REG          0x0004
  #define WDT_RESTART_REG             0x0008
  #define WDT_CTRL_REG                0x000C
  #define WDT_TIMEOUT_STATUS_REG      0x0010
  #define WDT_TIMEOUT_STATUS_CLR_REG  0x0014
  #define WDT_RESET_MASK1_REG         0x001C
  #define WDT_RESET_MASK2_REG         0x0020
  #define WDT_SW_RESET_MASK1_REG      0x0028   <------
  #define WDT_SW_RESET_MASK2_REG      0x002C
  #define WDT_SW_RESET_CTRL_REG       0x0024

Currently QEMU only cover a MMIO region of size 0x20:

  #define ASPEED_WDT_REGS_MAX        (0x20 / 4)

Change to map the whole 'iosize' which might be bigger, covering
the other registers. The MemoryRegionOps read/write handlers will
report the accesses as out-of-bounds guest-errors, but the next
commit will report them as unimplemented.

[1] https://github.com/AspeedTech-BMC/zephyr/releases/tag/v00.01.07
[2] https://github.com/AspeedTech-BMC/zephyr/commit/2e99f10ac27b
[3] https://github.com/AspeedTech-BMC/zephyr/blob/v00.01.08/drivers/watchdog/wdt_aspeed.c#L31

Reviewed-by: Peter Delevoryas <peter@pjd.dev>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>