Added dual-boot capable kernel and fs loading cmds.

Similar to how bootcmd is conditional, the loading commands are now as
well.  This makes it so that 'lk' and 'lf' change depending on whether
ACTIVATED_KERNEL_NAME is 'kernel1' or not.

The change is specifically where to install the kernel and fs, as well
as some macro cleanup for easier readability.

Change-Id: I2e0af3c87a7dd5bf2d3df316a5aa5d9618f9baa3
1 file changed