target: display: Add capability to skip primary panel in lk

In the current implementation, we have support to select a
specific oem panel in bootloader but there is no support for
skipping the panel configuration completely. This change adds
support to skip the panel configuration in bootloader and is
useful when there is no panel configuration available in
bootloader.

Usage: fastboot oem select-display-panel none

Change-Id: I8c4d558717ee3fd5ced418996a6b26b06ae45837
6 files changed