x86: Use tab instead of space to indent in PCIE_ECAM_BASE

Space is used before 'default' in PCIE_ECAM_BASE in arch/x86/Kconfig
so it looks misaligned. Replace the space with tab to indent.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2370c32..fef11f3 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -428,7 +428,7 @@
 
 config PCIE_ECAM_BASE
 	hex
-    default 0xe0000000
+	default 0xe0000000
 	help
 	  This is the memory-mapped address of PCI configuration space, which
 	  is only available through the Enhanced Configuration Access