mmc: renesas_sdhi: remove superfluous SCLKEN

mmc: renesas_sdhi: remove superfluous SCLKEN

All previously called functions handle SCLKEN on their own, no need to
enable it again in sdhi_reset().

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20201110162151.37622-4-wsa+renesas@sang-engineering.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>