mmc: exynos_dw_mmc: Don't call dwmci_setup_cfg() after add_dwmci()

mmc: exynos_dw_mmc: Don't call dwmci_setup_cfg() after add_dwmci()

add_dwmci() is already calling dwmci_setup_cfg() internally, there is no
needed to call dwmci_setup_cfg() again in case when add_dwmci() is used
(for non-DM cases). Fix it by calling dwmci_setup_cfg() only in DM
cases, when add_dwmci() wasn't called. Also, this assignment:

    host->mmc = &plat->mmc;

is wrong in non-DM case when add_dwmci() was called, as it's creating
mmc object internally. Fix that by pulling that assignment into DM case,
when add_dwmci() isn't called.

While at it, add also this missing assignment:

    host->mmc->dev = dev;

Fixes: 3537ee879e04 ("mmc: exynos_dw_mmc: support the Driver mode for Exynos")
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>