db845c|rb5: Switch to android-6.6 as the default kernel version

Switch db845c-userdebug and linaro_swr-userdebug target
builds to use android-6.6 prebuilt GKI binaries by default.

Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Change-Id: Ieb169f422f836c1d297d694d9b0c0fa67bbc54c3
2 files changed