configs: socfpga: fix building Stratix10 and Agilex

This fixes a merge error that accidentally left CONFIG_MTD_DEVICE
active by removing it from the config file.

Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>

include/configs/socfpga_soc64_common.h

@@ -62,7 +62,6 @@
 /*#define CONFIG_ENV_IS_IN_SPI_FLASH*/
 
 #ifndef CONFIG_SPL_BUILD
-#define CONFIG_MTD_DEVICE
 #define CONFIG_MTD_PARTITIONS
 #define MTDIDS_DEFAULT			"nor0=ff705000.spi.0"
 #endif /* CONFIG_SPL_BUILD */