emulation/qemu-power8: Select CPU_QEMU_POWER8

Change-Id: I5fa6486e96cd81767225a3e1015341c0c89053d1
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34115
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/mainboard/emulation/qemu-power8/Kconfig

@@ -19,6 +19,7 @@ if BOARD_EMULATION_QEMU_POWER8
 
 config BOARD_SPECIFIC_OPTIONS
 	def_bool y
+	select CPU_QEMU_POWER8
 	select BOARD_ROMSIZE_KB_4096
 	select ARCH_BOOTBLOCK_PPC64
 	select HAVE_UART_SPECIAL