efikamx: update to Efika MX Smarttop and Smartbook boards

efikamx: update to Efika MX Smarttop and Smartbook boards

This is a rework of a previously submitted patchset and bundles the
main board support and USB support into a single commit.

It requires the patch "mx5: add iomux-mx51.h include"

* Use iomux-mx51.h include to simplify board configuration.
* Simplify LED support (remove efikamx_toggle_led, change lit LEDs).
* Simplify MMC support for CD and WP pin differences.
* Fix broken CPU voltage setting - comment said 1.1V but the code set to
  1.2V. It should never have been set to 1.2V even on i.MX51 TO2 and
  all available Linux kernels would drop the voltage to 1.1V anyway and
  work reliably. This should lower power consumption during the boot
  process.
* Function renames for readability.
* Some board identification string changes to match actual product names.
* Passes checkpatch (v2)

Signed-off-by: Matt Sealey <matt@genesi-usa.com>
Cc: Stefano Babic <sbabic@denx.de>