power: reset: Add support for EMMC dload

Add sysfs entry to support emmc dload mode.
Adds /sys/kernel/reset/emmc_dload entry to enable or disable
emmc dload mode support.

Also include fix commit 1498330abf68 ("power: reset: Skip
emmc_dload sysfs entry creation").

Change-Id: If38135427304316b03d3193ad16d335605e9c143
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Lingutla Chandrasekhar <clingutla@codeaurora.org>