If you examine the symbol from the kernel compile (such as looking at the feature in “make nconfig” and seeing what the “CONFIG_…” is), I am guessing the symbol will contain “CONFIG_IXGBE…” (anything starting with “CONFIG_IXGBE”). If you then examine what the running kernel says is loaded, compare with your symbol:
zcat /proc/config.gz | grep IXGBE
What is the output of this? Does any of it say “=y”? Does any of it say “=m”?
What does “uname -r” say? Does this end with suffix “-tegra”? On your compiled kernel, did you specify this (which is what the default kernel would use):
CONFIG_LOCALVERSION="-tegra"