mx6: ddr: add routine to return DDR calibration data

Add routine mmdc_read_calibration() to return the output of DDR
calibration. This can be used for debugging or to aid in construction
of static memory configuration.

This routine will be used in a subsequent patch set adding a virtual
"mx6memcal" board, but could also be useful when gathering statistics
during an initial production run.

Signed-off-by: Eric Nelson <eric@nelint.com>
2 files changed