FROMGIT: PCI: Extend isolated function probing to LoongArch

Like s390 and the jailhouse hypervisor, LoongArch's PCI architecture allows
passing isolated PCI functions to a guest OS instance. So it is possible
that there is a multi-function device without function 0 for the host or
guest.

Allow probing such functions by adding a IS_ENABLED(CONFIG_LOONGARCH) case
in the hypervisor_isolated_pci_functions() helper.

This is similar to commit 189c6c3 ("PCI: Extend isolated function
probing to s390").

Signed-off-by: Huacai Chen <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Cc: [email protected]
Link: https://patch.msgid.link/[email protected]

(cherry picked from commit a02fd05
 https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next)
Signed-off-by: Kexy Biscuit <[email protected]>

Author: chenhuacai

include/linux/hypervisor.h

@@ -37,6 +37,9 @@ static inline bool hypervisor_isolated_pci_functions(void)
 	if (IS_ENABLED(CONFIG_S390))
 		return true;
 
+	if (IS_ENABLED(CONFIG_LOONGARCH))
+		return true;
+
 	return jailhouse_paravirt();
 }