* Add Makefile target `k70-som_config`.
 * Start K70-SOM board support code by cloning off the TWR-K70F120M
board-specific code.
 * Update DDR controller configuration to interact with the LPDDR memory chip.
Update timings for a 120 MHz DDR clock.
 * Remove configuration of pins NFC_D8..NFC_D15, they are not used by 8-bit NAND
flashes.
 * Optionally support 8-bit NAND flashes in the `fsl_nfc.c` driver.
 * Set correct size of RAM (64 MB).
 * Do not configure the LCD clock, because we do not support LCDs with K70-SOM
yet.
 * Update U-Boot prompt, IP address, MAC address, bootargs, hostname.