mmc: exynos_dw_mmc: Add support for ARM64 Exynos chips

Add the compatible entry and corresponding chip data for Exynos7
compatible chips, which covers modern ARM64 based Exynos chips. They
have some differences w.r.t. old ARM32 Exynos chips:
  - CLKSEL register offset is different
  - 64-bit IDMAC descriptor and 64-bit IDMAC registers are used
    (implemented in dw_mmc core driver)

In terms of the driver implementation, the CIU clock is obtained via CCF
framework (as opposed to ad-hoc clock driver implementation for ARM32
chips).

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

arch/arm/mach-exynos/include/mach/dwmmc.h

@@ -8,6 +8,7 @@
 #define __ASM_ARM_ARCH_DWMMC_H
 
 #define DWMCI_CLKSEL		0x09C
+#define DWMCI_CLKSEL64		0x0a8
 #define DWMCI_SET_SAMPLE_CLK(x)	(x)
 #define DWMCI_SET_DRV_CLK(x)	((x) << 16)
 #define DWMCI_SET_DIV_RATIO(x)	((x) << 24)

drivers/mmc/exynos_dw_mmc.c

@@ -385,6 +385,11 @@ static const struct exynos_dwmmc_variant exynos5_drv_data = {
 #endif
 };
 
+static const struct exynos_dwmmc_variant exynos7_smu_drv_data = {
+	.clksel	= DWMCI_CLKSEL64,
+	.quirks	= DWMCI_QUIRK_DISABLE_SMU,
+};
+
 static const struct udevice_id exynos_dwmmc_ids[] = {
 	{
 		.compatible	= "samsung,exynos4412-dw-mshc",
@@ -392,6 +397,9 @@ static const struct udevice_id exynos_dwmmc_ids[] = {
 	}, {
 		.compatible	= "samsung,exynos-dwmmc",
 		.data		= (ulong)&exynos5_drv_data,
+	}, {
+		.compatible	= "samsung,exynos7-dw-mshc-smu",
+		.data		= (ulong)&exynos7_smu_drv_data,
 	},
 	{ }
 };