mmc: sdhci-esdhc: Make 8BIT bus work

commit 8e91125ff3f57f15c6568e2a6d32743b3f7815e4 upstream.

Support for 8BIT bus with was added some time ago to sdhci-esdhc but
then missed to remove the 8BIT from the reserved bit mask which made
8BIT non functional.

Fixes: 66b50a00992d ("mmc: esdhc: Add support for 8-bit bus width and..")
Signed-off-by: Joakim Tjernlund <joakim.tjernlund@transmode.se>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>