src/mainboard/emulation/qemu-power9/*: add QEMU POWER9 mainboard

Add initial implementation for booting on QEMU POWER9 emulation.

Change-Id: I079c5b9ad564024dd13296ef75c263bdc40c9d39
Signed-off-by: Yaroslav Kurlaev <yaroslav.kurlaev@3mdeb.com>
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57079
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Michał Żygowski <michal.zygowski@3mdeb.com>
diff --git a/configs/config.emulation_qemu_power9 b/configs/config.emulation_qemu_power9
new file mode 100644
index 0000000..7f64ee8
--- /dev/null
+++ b/configs/config.emulation_qemu_power9
@@ -0,0 +1 @@
+CONFIG_BOARD_EMULATION_QEMU_POWER9=y