target: Support display prefix string for kernel cmd line

MSM8610 target uses different mdp kernel driver
compared to other target. These kernel drivers are
going to use module_param to parse the kernel command
line parameters instead of "choosen" node parsing.
GCDB can use the DISPLAY_CMDLINE_PREFIX string
to format correct kernel command line argument based
on target.

Change-Id: Ifa4667f0244f3b56b9f6e14dc3fe328f9ebc8cfd
4 files changed