mb/google/rex: Enable PMC IPC config

TEST=Able to build and boot Google/Rex.

Device (PMC)
{
    Name (_HID, "INTC1026")  // _HID: Hardware ID
    Name (_DDN, "Intel(R) Meteor Lake IPC Controller")  // _DDN: DOS Dev
ice Name
    Method (_STA, 0, NotSerialized)  // _STA: Status
    {
         Return (0x0B)
    }
    ...
}

Signed-off-by: Subrata Banik <subratabanik@google.com>
Change-Id: I28c0153a770b36cde0653ac92d2e5ad1b8dd3449
Reviewed-on: https://review.coreboot.org/c/coreboot/+/71268
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Kapil Porwal <kapilporwal@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/rex/Kconfig

@@ -22,6 +22,7 @@ config BOARD_GOOGLE_REX_COMMON
 	select I2C_TPM
 	select INTEL_LPSS_UART_FOR_CONSOLE
 	select MAINBOARD_HAS_TPM2
+	select PMC_IPC_ACPI_INTERFACE
 	select SOC_INTEL_CSE_LITE_SKU
 
 config BOARD_GOOGLE_BASEBOARD_REX