T30:
- board.c: changes required by different PMIC variant
colibri_t20/colibri_t30: device tree compatibility matching

Include "colibri_" prefix in our board compatibility tables in
preparation to properly distinguish future e.g. Apalis modules.

While at it bring the device tree matching more in par with Linux
kernel 3.1.10 from NVIDIA's L4T R16-R2.
colibri_t30: USB: fix Ethernet detection fault

Turns out our simplistic approach of just blindly enabling LAN_V_BUS
and releasing LAN_RESET_N does not prove very reliable.
Properly resetting the chip for 5 microseconds after VBUS is stable
just like we do on the Colibri T20 seems to fix the issue.
colibri_t20: add optional 800x480 timing

Add optional aka commented out 800x480@60 timing suitable for EDT
ET070080DH6.
u-boot: compile with -O2, some compilers can't cope with -Os
T30: define USE_PRIVATE_LIBGCC, oe-core can't build without
toradex: common: clean-up board file

This is a purely cosmetic clean-up of the common Toradex board file.
T30: cmdline with ext3 rootfs, not ext2
T30: cmdline with rootfs mounted noatime, not the default relatime
colibri_t30: migrate to proper machine type

After having registered the following proper machine type migrate to
actually using it.

http://www.arm.linux.org.uk/developer/machines/list.php?id=4493

While at it clean-out some obsolete Cardhu specific device-tree
nodes resp. properties and clean-up the mach-types header file as well.
colibri_t30: fix MMC/SD card detect GPIO

The Colibri T30 V1.1 modules actually use a different card detect GPIO.