On the Tegras we currently use uImage. (Which you tried to build with make uImage …)
So you shouldn’t expect a zImage.
The last lines of your build log shows the following
"mkimage" command not found - U-Boot images will not be built
make[1]: *** [arch/arm/boot/uImage] Error 1
make: *** [uImage] Error 2
which means your build did fail because you don’t have the U-Boot mkimage utility in your path.
Please revisit here do get the instructions on how to get the tool.
Note that you did not yet compile the kernel modules. This includes the explanation of what gets compiled as a kernel module.
The following explains how you deploy the kernel and the kernel modules onto a module.
Max