[Intel][6.6] SPI and SMBus driver support on DMR

[juntian]

Description

Add SMBus and SPI NOR Flash drivers for DMR.

Test (Manual)

1. Build sanity

make ARCH=x86_64 defconfig   # or your DMR platform config in velinux-kernel-intel/config.x86_64
#ensure CONFIG_I2C_I801=y/m and CONFIG_SPI_INTEL / CONFIG_SPI_INTEL_PCI=y/m
make drivers/i2c/busses/i2c-i801.o drivers/spi/spi-intel-pci.o

Confirm no compile warnings/errors from the new device-ID lines.

2. Confirm the PCI devices exist on the DMR box

lspci -nn | grep -Ei '8086:5827|8086:5825'

You should see the SMBus controller (5827) and PCH/PCU SPI controller (5825) listed with Serial bus controller [0c05] / Unclassified or Non-VGA class for SPI depending on platform.

3. Verify i2c-i801 binds and SMBus works

dmesg | grep -i i801                 # should show "SMBus I801 adapter ... at <bar>"
i2cdetect -l                         # new "SMBus I801 adapter" should appear
i2cdetect -y <bus_number>            # scan for any SMBus/I2C devices behind it (SPD EEPROMs, sensors, etc.)

4. Verify spi-intel binds and flash is detected

dmesg | grep -i "spi.intel\|Serial Flash"
ls /sys/bus/spi/devices/
cat /proc/mtd                        # look for the new mtd entry (BIOS/descriptor region)
mtdinfo /dev/mtd0                    # size, erase size, should match expected flash chip

[guixiongwei]

could you evaluate the SPI/SMBus support on LKVS?