sh: Remove sh7757lcr board

This board has not been converted to CONFIG_DM by the deadline of v2020.01
and is missing other conversions which depend on this as well.  Remove it.

As this is the last SH4A board, remove that support as well.

Cc: Marek Vasut <marek.vasut+renesas@gmail.com>
Signed-off-by: Tom Rini <trini@konsulko.com>

configs/sh7757lcr_defconfig

@@ -1,40 +0,0 @@
-CONFIG_SH=y
-CONFIG_SYS_TEXT_BASE=0x8ef80000
-CONFIG_ENV_SIZE=0x10000
-CONFIG_SH_32BIT=y
-CONFIG_TARGET_SH7757LCR=y
-CONFIG_BOOTDELAY=3
-CONFIG_USE_BOOTARGS=y
-CONFIG_BOOTARGS="console=ttySC2,115200 root=/dev/nfs ip=dhcp"
-# CONFIG_CMDLINE_EDITING is not set
-# CONFIG_AUTO_COMPLETE is not set
-# CONFIG_CMD_BDI is not set
-# CONFIG_CMD_CONSOLE is not set
-# CONFIG_CMD_BOOTD is not set
-# CONFIG_CMD_IMI is not set
-# CONFIG_CMD_XIMG is not set
-# CONFIG_CMD_EDITENV is not set
-# CONFIG_CMD_ENV_EXISTS is not set
-CONFIG_CMD_MD5SUM=y
-# CONFIG_CMD_LOADB is not set
-CONFIG_CMD_MMC=y
-CONFIG_CMD_SDRAM=y
-# CONFIG_CMD_ECHO is not set
-# CONFIG_CMD_ITEST is not set
-# CONFIG_CMD_SOURCE is not set
-# CONFIG_CMD_SETEXPR is not set
-CONFIG_CMD_MII=y
-CONFIG_CMD_PING=y
-# CONFIG_CMD_SLEEP is not set
-CONFIG_CMD_EXT2=y
-CONFIG_MAC_PARTITION=y
-CONFIG_DOS_PARTITION=y
-CONFIG_ENV_OVERWRITE=y
-CONFIG_VERSION_VARIABLE=y
-CONFIG_MMC=y
-CONFIG_SH_MMCIF=y
-CONFIG_BITBANGMII=y
-CONFIG_SH_ETHER=y
-CONFIG_SCIF_CONSOLE=y
-CONFIG_SPI=y
-CONFIG_USE_PRIVATE_LIBGCC=y