Comment # 11 on bug 1019337 from Takashi Iwai

OK, then check /usr/lib/dracut/modules.d/90kernel-modules/module-setup.sh.
There is a part like:

        hostonly='' instmods \
            sr_mod sd_mod scsi_dh ata_piix hid_generic unix \
            ehci-hcd ehci-pci ehci-platform \
            ohci-hcd ohci-pci \
            uhci-hcd \
            xhci-hcd xhci-pci xhci-plat-hcd \
            pinctrl-cherryview

If pinctrl-cherryview isn't present, add it like the above.
Then, append also pwm-lpss and i2c-designware-platform, too.

After changing it, rebuild initrd, and retest.

Also, another way would be to rebuild initrd with "-o drm" option so that i915
module won't be loaded in initrd.