Revert "arch/arm: mach-tegra: cpu tegra: Ignore return value"

This reverts commit 88f9cff2136a9ea9890b3001e4fa1bdf354f9541.
Fix bugs with current flags:  Use -Os since -O2 is unstable in gcc 4.8

currently

Signed-off-by: Paul Beeler <sparksco@gmail.com>