app: aboot: Remove display kernel cmdline argument prefix
app: aboot: Remove display kernel cmdline argument prefix

aboot adds the hardcoded prefix string "mdss_mdp.panel"
for display kernel command line argument. This
hardcoded prefix string usage is removed because
it is replaced by GCDB with dynamic prefix argument.

Change-Id: Ie6ce0187bfbb8cc52a482ec78bdd1e7925e61b8b

M1cha/lktris,jsr-d10/android_bootable_bootloader_lk,jsr-d10/android_bootable_bootloader_lk,CanarySolutions/little-kernel,jsr-d10/android_bootable_bootloader_lk,M1cha/android_bootable_bootloader_lk,Foxda-Tech/polaris-bootable-bootloader-lk,jsr-d10/android_bootable_bootloader_lk,CanarySolutions/little-kernel,Foxda-Tech/argo8-bootable-bootloader-lk,CanarySolutions/little-kernel,Foxda-Tech/argo8-bootable-bootloader-lk,M1cha/android_bootable_bootloader_lk,Foxda-Tech/polaris-bootable-bootloader-lk,M1cha/android_bootable_bootloader_lk,Foxda-Tech/polaris-bootable-bootloader-lk,Foxda-Tech/argo8-bootable-bootloader-lk,M1cha/lktris,efidroid/lk,M1cha/android_bootable_bootloader_lk,M1cha/lktris,efidroid/lk,jsr-d10/android_bootable_bootloader_lk,Foxda-Tech/argo8-bootable-bootloader-lk,efidroid/lk,CanarySolutions/little-kernel,M1cha/android_bootable_bootloader_lk,CanarySolutions/little-kernel,M1cha/android_bootable_bootloader_lk,M1cha/lktris,M1cha/lktris,Foxda-Tech/argo8-bootable-bootloader-lk,efidroid/lk,Foxda-Tech/polaris-bootable-bootloader-lk,Foxda-Tech/polaris-bootable-bootloader-lk,efidroid/lk