mmc: exynos_dw_mmc: Add quirk for disabling FMP

mmc: exynos_dw_mmc: Add quirk for disabling FMP

Add DWMCI_QUIRK_DISABLE_FMP which disables Flash Memory Protector (FMP)
during driver's init. It's usually done by early bootloaders, but in
some cases (like USB boot) the FMP may be left unconfigured. The issue
was observed on Exynos850 SoC (the E850-96 board). Enabling this quirk
makes eMMC functional even in such cases.

No functional change, as this feature is only added here but not enabled
for any chips yet.

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>