Revert "efi/x86: Set the PE/COFF header's NX compat flag unconditionally"

This reverts commit 891f889.

Revert because of compatibility issues of MS Surface devices and GRUB
with NX. In short, these devices get stuck on boot with NX advertised.
So to not advertise it, add the respective option back in.

Signed-off-by: Maximilian Luz <[email protected]>
Patchset: secureboot

Author: qzed

arch/x86/boot/header.S

@@ -111,7 +111,11 @@ extra_header_fields:
 	.long	salign				# SizeOfHeaders
 	.long	0				# CheckSum
 	.word	IMAGE_SUBSYSTEM_EFI_APPLICATION	# Subsystem (EFI application)
+#ifdef CONFIG_EFI_DXE_MEM_ATTRIBUTES
 	.word	IMAGE_DLL_CHARACTERISTICS_NX_COMPAT	# DllCharacteristics
+#else
+	.word	0				# DllCharacteristics
+#endif
 #ifdef CONFIG_X86_32
 	.long	0				# SizeOfStackReserve
 	.long	0				# SizeOfStackCommit