Revert "mmc: core: increase delay between power-up and power-on"

This reverts commit 3ec1ed2a.

The original 10ms delay is enough to reach power on from power
up. Increase delay is workaround to resovle resume Re-init
retries time out error. The root cause is additional QDSD block
would impact SD fucntionality as they are multiplex with SD
interface. If cd-gpio is HW floating and has a pulse, QDSD 100ms
search process would be triggerred is prior to SD block and SD
interface work as QDSD instead of SD.

The fix is merged, so revert the workaround.

Change-Id: I647be754de4a6a13678cbb1456a9db88c2714f94
Signed-off-by: Guoping Yu <guopingy@codeaurora.org>