x86: Create more space for SPL with qemu-x86_64

The space here is quite tight and there is plenty of room in the ROM.
Move SPL earlier to allow for expansion.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/qemu-x86_64_defconfig b/configs/qemu-x86_64_defconfig
index 3c0fc7a..39375c7 100644
--- a/configs/qemu-x86_64_defconfig
+++ b/configs/qemu-x86_64_defconfig
@@ -7,7 +7,7 @@
 CONFIG_SPL_DM_SPI=y
 CONFIG_DEFAULT_DEVICE_TREE="qemu-x86_i440fx"
 CONFIG_SPL_SYS_MALLOC_F_LEN=0x2000
-CONFIG_SPL_TEXT_BASE=0xfffd4000
+CONFIG_SPL_TEXT_BASE=0xfffd0000
 CONFIG_DEBUG_UART_BASE=0x3f8
 CONFIG_DEBUG_UART_CLOCK=1843200
 CONFIG_X86_RUN_64BIT=y