mmc: exynos_dw_mmc: Add exynos850 compatible

mmc: exynos_dw_mmc: Add exynos850 compatible

Up until now "samsung,exynos7-dw-mshc-smu" compatible was used for
Exynos850 SoC, as it's present in its device tree. But Exynos850 device
tree also supports "samsung,exynos850-dw-mshc-smu" compatible string.
Add it in compatible ID list in the driver so that it can be matched
against this string for Exynos850 device tree.

No functional change, as the driver data is just a copy of
"samsung,exynos7-dw-mshc-smu" data for now.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>