genericarm64: add ttyPS1 for KV260

The AMD KV260 has a serial console on ttyPS1, so until we can dynamically
detect the console under sysvinit we can add it to SERIAL_CONSOLES so
this platform has a working console when not running systemd.

(From meta-yocto rev: 467b6d77e50f92bee3c8f7ca928bd70758bab457)

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta-yocto-bsp/conf/machine/genericarm64.conf

@@ -28,7 +28,7 @@ WKS_FILE ?= "genericarm64.wks.in"
 EFI_PROVIDER ?= "${@bb.utils.contains("DISTRO_FEATURES", "systemd", "systemd-boot", "grub-efi", d)}"
 
 # Try to bring up a selection of physical or virtual serial consoles
-SERIAL_CONSOLES ?= "115200;ttyAMA0 115200;hvc0 115200;ttyS0 115200;ttyS1 115200;ttyS2"
+SERIAL_CONSOLES ?= "115200;ttyAMA0 115200;hvc0 115200;ttyS0 115200;ttyS1 115200;ttyS2 115200;ttyPS1"
 
 # Allow u-boot to be built for use with qemu-system-aarch64.
 # This u-boot is _not_ suitable for use with real hardware, and the expectation