ppc: Remove MPC8544DS board

This board relies on using CONFIG_LIBATA but does not enable CONFIG_AHCI.  The
deadline for this conversion was the v2019.07 release.  The use of CONFIG_AHCI
requires CONFIG_DM.  The deadline for this conversion was v2020.01.  Remove
this board.

Cc: Priyanka Jain <priyanka.jain@nxp.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>

configs/MPC8544DS_defconfig

@@ -1,52 +0,0 @@
-CONFIG_PPC=y
-CONFIG_SYS_TEXT_BASE=0xFFF80000
-CONFIG_ENV_SIZE=0x2000
-CONFIG_ENV_SECT_SIZE=0x10000
-CONFIG_MPC85xx=y
-# CONFIG_CMD_ERRATA is not set
-CONFIG_TARGET_MPC8544DS=y
-CONFIG_OF_BOARD_SETUP=y
-CONFIG_OF_STDOUT_VIA_ALIAS=y
-CONFIG_BOOTDELAY=10
-# CONFIG_CONSOLE_MUX is not set
-# CONFIG_MISC_INIT_R is not set
-CONFIG_HUSH_PARSER=y
-CONFIG_CMD_REGINFO=y
-CONFIG_CMD_IMLS=y
-CONFIG_CMD_I2C=y
-CONFIG_CMD_PCI=y
-CONFIG_CMD_USB=y
-CONFIG_CMD_DHCP=y
-CONFIG_CMD_MII=y
-CONFIG_CMD_PING=y
-# CONFIG_CMD_HASH is not set
-CONFIG_CMD_EXT2=y
-CONFIG_ENV_OVERWRITE=y
-CONFIG_ENV_IS_IN_FLASH=y
-CONFIG_ENV_ADDR=0xFFF70000
-CONFIG_SCSI_AHCI=y
-# CONFIG_MMC is not set
-CONFIG_MTD_NOR_FLASH=y
-CONFIG_FLASH_CFI_DRIVER=y
-CONFIG_SYS_FLASH_CFI=y
-CONFIG_PHY_ATHEROS=y
-CONFIG_PHY_BROADCOM=y
-CONFIG_PHY_DAVICOM=y
-CONFIG_PHY_LXT=y
-CONFIG_PHY_MARVELL=y
-CONFIG_PHY_NATSEMI=y
-CONFIG_PHY_REALTEK=y
-CONFIG_PHY_SMSC=y
-CONFIG_PHY_VITESSE=y
-CONFIG_PHY_GIGE=y
-CONFIG_E1000=y
-CONFIG_MII=y
-CONFIG_RTL8139=y
-CONFIG_TSEC_ENET=y
-CONFIG_SCSI=y
-CONFIG_SYS_NS16550=y
-CONFIG_USB=y
-CONFIG_USB_EHCI_PCI=y
-CONFIG_USB_STORAGE=y
-CONFIG_VIDEO=y
-CONFIG_OF_LIBFDT=y