ti: remove usage of DM_I2C_COMPAT and don't disable DM_I2C in SPL

DM_I2C_COMPAT is a compatibility layer that allows using the non-DM I2C
API when DM_I2C is used. The goal is to eventually remove DM_I2C_COMPAT
when all I2C "clients" have been migrated to use the DM API.
This a step in that direction for the TI based platforms.
Build tested with buildman:
buildman -dle am33xx ti omap3 omap4 omap5 davinci keystone

boot tested with:
am335x_evm, am335x_boneblack, am335x_boneblack_vboot (DM version),
am57xx_evm, dra7xx_evm, k2g_evm, am437x_evm

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
diff --git a/arch/arm/mach-keystone/ddr3_spd.c b/arch/arm/mach-keystone/ddr3_spd.c
index 2613092..6eee9ad 100644
--- a/arch/arm/mach-keystone/ddr3_spd.c
+++ b/arch/arm/mach-keystone/ddr3_spd.c
@@ -403,6 +403,7 @@
 static int ddr3_read_spd(ddr3_spd_eeprom_t *spd_params)
 {
 	int ret;
+#ifndef CONFIG_DM_I2C
 	int old_bus;
 
 	i2c_init(CONFIG_SYS_DAVINCI_I2C_SPEED, CONFIG_SYS_DAVINCI_I2C_SLAVE);
@@ -413,7 +414,13 @@
 	ret = i2c_read(0x53, 0, 1, (unsigned char *)spd_params, 256);
 
 	i2c_set_bus_num(old_bus);
+#else
+	struct udevice *dev;
 
+	ret = i2c_get_chip_for_busnum(1, 0x53, 1, &dev);
+	if (!ret)
+		ret = dm_i2c_read(dev, 0, (unsigned char *)spd_params, 256);
+#endif
 	if (ret) {
 		printf("Cannot read DIMM params\n");
 		return 1;