emmc/dw_mmc: fix the assert on HLE bit ...

When check HLE bit in interrupt register, it should check whether
HLE bit is set, not clear.

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>

Use SPDX license identifiers ...

To make software license auditing simpler, use SPDX[0] license
identifiers instead of duplicating the license text in every file.

NOTE: Files that have been imported by FreeBSD have not been modified.

[0]: https://spdx.org/

Change-Id: I80a00e1f641b8cc075ca5a95b10607ed9ed8761a
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>

drivers: add designware emmc driver ...

Support Designware eMMC driver. It's based on both IO block
and eMMC driver.

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>