configs: vim3: use the vim3 board support

Use the newly added VIM3 board support instead of the generic W400.
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>
Reviewed-by: NKevin Hilman <khilman@baylibre.com>
Tested-by: NKevin Hilman <khilman@baylibre.com>
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>

configs/khadas-vim3_defconfig

 CONFIG_ARM=y
-CONFIG_SYS_BOARD="w400"
+CONFIG_SYS_BOARD="vim3"
 CONFIG_ARCH_MESON=y
 CONFIG_SYS_TEXT_BASE=0x01000000
 CONFIG_NR_DRAM_BANKS=1

configs/khadas-vim3l_defconfig

 CONFIG_ARM=y
-CONFIG_SYS_BOARD="w400"
+CONFIG_SYS_BOARD="vim3"
 CONFIG_ARCH_MESON=y
 CONFIG_SYS_TEXT_BASE=0x01000000
 CONFIG_NR_DRAM_BANKS=1