mx6: Add board mx6memcal for use in validating DDR

This is a virtual "board" that uses configuration files and
Kconfig to define the memory layout used by a real board during
the board bring-up process.

It generates an SPL image that can be loaded using imx_usb or
SB_LOADER.exe.

When run, it will generate a set of calibration constants for
use in either or both a DCD configuration file for boards that
use u-boot.imx or struct mx6_mmdc_calibration for boards that
boot via SPL.

In essence, it is a configurable, open-source variant of the
Freescale ddr-stress tool.

	https://community.nxp.com/docs/DOC-105652

File mx6memcal_defconfig configures the board for use with
mx6sabresd or mx6qsabreauto.

Signed-off-by: Eric Nelson <eric@nelint.com>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
diff --git a/board/freescale/mx6memcal/MAINTAINERS b/board/freescale/mx6memcal/MAINTAINERS
new file mode 100644
index 0000000..5da38f7
--- /dev/null
+++ b/board/freescale/mx6memcal/MAINTAINERS
@@ -0,0 +1,7 @@
+MX6MEMCAL BOARD
+M:	Eric Nelson <eric@nelint.com>
+S:	Maintained
+F:	board/freescale/mx6memcal/
+F:	include/configs/mx6memcal.h
+F:	configs/mx6memcal_defconfig
+