Merge tag 'arc-more-updates-for-2018.11-rc2-2' of git://git.denx.de/u-boot-arc

More fixes and improvements for ARC here:

Fixes (this time included for real):
 * Take care of global uninitialized variables
   They used to be put right after .bss section and were never
   zeroed as they should be. Now merged with normal .bss

Improvements:
 * Print more verbose CPU info for boards built on real silicon
 * Add support for SD-card detection on all ARC boards
 * Quite a few fixes for IoT DK
   - Support reset by command
   - Print of CPU freq on boot
   - Link for eFlash etc