x86: set SPECTRE_BHI_ON as default

commit 2bb69f5 upstream.

Part of a merge commit from Linus that adjusted the default setting of
SPECTRE_BHI_ON.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/x86/Kconfig

@@ -2508,7 +2508,7 @@ config MITIGATION_RFDS
 choice
 	prompt "Clear branch history"
 	depends on CPU_SUP_INTEL
-	default SPECTRE_BHI_AUTO
+	default SPECTRE_BHI_ON
 	help
 	  Enable BHI mitigations. BHI attacks are a form of Spectre V2 attacks
 	  where the branch history buffer is poisoned to speculatively steer