ARM: rmobile: Remove CONFIG_CMD_SDRAM from Salvator-X

This command is useless on Salvator-X as it is reading DRAM info from
SPD. We have no SPD on Salvator-X.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>

configs/r8a7795_salvator-x_defconfig

@@ -14,7 +14,6 @@ CONFIG_HUSH_PARSER=y
 CONFIG_CMD_BOOTZ=y
 CONFIG_CMD_GPIO=y
 CONFIG_CMD_MMC=y
-CONFIG_CMD_SDRAM=y
 CONFIG_CMD_USB=y
 CONFIG_CMD_DHCP=y
 CONFIG_CMD_MII=y

configs/r8a7796_salvator-x_defconfig

@@ -15,7 +15,6 @@ CONFIG_HUSH_PARSER=y
 CONFIG_CMD_BOOTZ=y
 CONFIG_CMD_GPIO=y
 CONFIG_CMD_MMC=y
-CONFIG_CMD_SDRAM=y
 CONFIG_CMD_USB=y
 CONFIG_CMD_DHCP=y
 CONFIG_CMD_MII=y