DEBUG_FS used to be selected by COMMON_CLK_DEBUG, which was enabled
by tegra_defconfig. However, this config option no longer exists, so
no longer selects DEBUG_FS, and nothing else selects it either. So,
"make tegra_defconfig" no longer enables DEBUG_FS in .config.

Rebuild tegra_defconfig on top of next-20140424, while manually
re-enabling DEBUG_FS.

Reasons for removed entries are:
- I2C_MUX: selected by MEDIA_SUBDRV_AUTOSELECT
- DRM_PANEL: selected by DRM_TEGRA
- NEW_LEDS: selected by many things; at least VT
- LEDS_CLASS: selected by many things; at least VT
- LEDS_TRIGGERS: selected by many things; at least VT
- COMMON_CLK_DEBUG: no longer exists
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>