mmc: sdhci-pci-o2micro: Bug fix for SDR104 HW tuning failure

Force chip enter L0 power state during SDR104 HW tuning to avoid tuning failure

Signed-off-by: Shirley Her <shirley.her@bayhubtech.com>
Link: https://lore.kernel.org/r/20210206014051.3418-1-shirley.her@bayhubtech.com
Fixes: 7b7d897e

 ("mmc: sdhci-pci-o2micro: Add HW tuning for SDR104 mode")
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>