psplash: Make psplash wait for the framebuffer to be ready

Especially with systemd its seen that psplash-start service starts
before /dev/fb0 is created by kernel which results in

[FAILED] Failed to start Start psplash boot splash screen.

this is quite frequent race now with kernel 6.1

Add device dependency on sys-devices-platform-gpu-graphics-fb0.device
via a unit file drop-in

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Leon Anavi <leon.anavi@konsulko.com>

recipes-core/psplash/files/framebuf.conf

@@ -0,0 +1,4 @@
+[Unit]
+Requires=sys-devices-platform-gpu-graphics-fb0.device
+After=sys-devices-platform-gpu-graphics-fb0.device
+

recipes-core/psplash/psplash_%.bbappend

@@ -1,2 +1,12 @@
 FILESEXTRAPATHS:prepend := "${THISDIR}/files:"
 SPLASH_IMAGES:rpi = "file://psplash-raspberrypi-img.h;outsuffix=raspberrypi"
+
+SRC_URI:append:rpi = " file://framebuf.conf"
+
+do_install:append:rpi() {
+    if [ "${@bb.utils.filter('DISTRO_FEATURES', 'systemd', d)}" ]; then
+        install -Dm 0644 ${WORKDIR}/framebuf.conf ${D}${systemd_system_unitdir}/psplash-start.service.d/framebuf.conf
+    fi
+}
+
+FILES:${PN}:append:rpi = " ${systemd_system_unitdir}/psplash-start.service.d"