[PATCH v4 0/4]implement eMMC4.4 standard HW reset feature

[Chuanxiao Dong <chuanxiao.dong@intel.com>]

Hi,
	These are the version 4 patches to implement eMMC4.4 HW reset
	feature. Host controller can use this feature by trigger RST_n signal.
	To enable this, byte 162 of EXT_CSD register should be set.
	HW reset is implemented in mmc core layer and sdhci host layer, and it
	will be used after each reading/writing/erasing timeout error occures.

	change-log:
	This version change the way to detect timeout error conditions. Added a
	new routine mmc_handle_timeout_error to do this instead to do this in
	mmc_wait_for_req. Each timeout read/write/erase command can use this
	routine to do HW reset.

	patch1: enable HW reset capability if card support.

	patch2: add two new callback to implement HW reset in mmc core layer. In
	this patch, routine mmc_handle_timeout_error was added.

	patch3: implement hardware_reset callback for sdhci host. A new callback
	reset_emmc was defined which will be each sdhci host controller to
	implement separately.

	patch4: did a HW reset after each read/write/erase command.

Thanks
Chuanxiao