apq8084: Enable SDHCI HS400 mode for APQ8084.
apq8084: Enable SDHCI HS400 mode for APQ8084.

Use target specific config option to enable HS400 mode.

Change-Id: I05193269b680306311935c4a3a148c3fea2e6e79

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