x86: dfi-bt700: Adjust CONFIG_TEXT_BASE

At present U-Boot no longer builds as a complete rom for all the
configs of dfi-bt700.

    BINMAN  .binman_stamp
  Wrote map file './rom.map' to show errors
  binman: Section '/binman/rom': contents size 0x80e836 (8448054) exceeds section size 0x800000 (8388608)

Checking rom.map we see 'intel-vga' section is overlapped with
other sections:

  <none>     fff00000  000aac90  u-boot-with-ucode-ptr
  <none>     fffa0000  00010000  intel-vga
  <none>     fffaac90  00001df0  u-boot-dtb-with-ucode
  <none>     fffaca80  00019800  u-boot-ucode

Let's adjust CONFIG_TEXT_BASE to allow more space for U-Boot codes.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/configs/theadorable-x86-dfi-bt700_defconfig b/configs/theadorable-x86-dfi-bt700_defconfig
index 4755b47..fea35cd 100644
--- a/configs/theadorable-x86-dfi-bt700_defconfig
+++ b/configs/theadorable-x86-dfi-bt700_defconfig
@@ -1,5 +1,5 @@
 CONFIG_X86=y
-CONFIG_TEXT_BASE=0xFFF00000
+CONFIG_TEXT_BASE=0xFFE00000
 CONFIG_NR_DRAM_BANKS=8
 CONFIG_ENV_SIZE=0x2000
 CONFIG_ENV_OFFSET=0x6EC000