x86: Disable DM_PCI_COMPAT

Now that all x86 codes have been converted to use proper DM PCI APIs,
it's time to disable the legacy compatible layer.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index a995e32..49e173c 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -93,9 +93,6 @@
 	depends on X86_RESET_VECTOR
 	default 0xfffff800
 
-config DM_PCI_COMPAT
-	default y	# Until we finish moving over to the new API
-
 config BOARD_ROMSIZE_KB_512
 	bool
 config BOARD_ROMSIZE_KB_1024