aspeed: ast27x0: Map unimplemented devices in SoC memory

aspeed: ast27x0: Map unimplemented devices in SoC memory

Maps following unimplemented devices in SoC memory
- dpmcu
- iomem
- iomem0
- iomem1
- ltpi

Iomem, Iomem0 and Iomem1 include unimplemented controllers in the memory ranges 0x0 - 0x1000000, 0x120000000 - 0x121000000 and
0x14000000 - 0x141000000.

For instance:
- USB hub at 0x12010000
- eSPI at 0x14C5000
- PWM at 0x140C0000

DPMCU stands for Display Port MCU controller. LTPI is used to connect to AST1700.
AST1700 is an I/O expander that supports the DC-SCM 2.1 LTPI protocol.
It provides AST2700 with additional GPIO, UART, I3C, and other interfaces.

Signed-off-by: Steven Lee <steven_lee@aspeedtech.com>
Change-Id: Iae4db49a4818af3e2c43c16a27fc76329d2405d6
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250502103449.3091642-2-steven_lee@aspeedtech.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>