iommu/amd: Fix compile warning in init code

BugLink: https://bugs.launchpad.net/bugs/2080378

A recent commit introduced these compile warnings:

  CC      drivers/iommu/amd/init.o
drivers/iommu/amd/init.c:938:12: error: ‘iommu_init_ga_log’ defined but not used [-Werror=unused-function]
  938 | static int iommu_init_ga_log(struct amd_iommu *iommu)
      |            ^~~~~~~~~~~~~~~~~
drivers/iommu/amd/init.c:902:12: error: ‘iommu_ga_log_enable’ defined but not used [-Werror=unused-function]
  902 | static int iommu_ga_log_enable(struct amd_iommu *iommu)
      |            ^~~~~~~~~~~~~~~~~~~

The warnings appear because both functions are defined when IRQ
remapping is not enabled, but only used when IRQ remapping is enabled.

Fix it by only defining the functions when IRQ remapping is enabled.

Fixes: c5e1a1e ("iommu/amd: Simplify and Consolidate Virtual APIC (AVIC) Enablement")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20220729100432.22474-1-joro@8bytes.org
(backported from commit be280ea)
[ghadi-rahme: Had to adjust the context due to missing commits]
Signed-off-by: Ghadi Elie Rahme <ghadi.rahme@canonical.com>
Acked-by: Guoqing Jiang <guoqing.jiang@canonical.com>
Acked-by: Ivan Hu <ivan.hu@canonical.com>
Signed-off-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>

Author: joergroedel

drivers/iommu/amd/init.c

@@ -816,9 +816,9 @@ static void free_ga_log(struct amd_iommu *iommu)
 #endif
 }
 
+#ifdef CONFIG_IRQ_REMAP
 static int iommu_ga_log_enable(struct amd_iommu *iommu)
 {
-#ifdef CONFIG_IRQ_REMAP
 	u32 status, i;
 	u64 entry;
 
@@ -848,13 +848,12 @@ static int iommu_ga_log_enable(struct amd_iommu *iommu)
 
 	if (WARN_ON(i >= LOOP_TIMEOUT))
 		return -EINVAL;
-#endif /* CONFIG_IRQ_REMAP */
+
 	return 0;
 }
 
 static int iommu_init_ga_log(struct amd_iommu *iommu)
 {
-#ifdef CONFIG_IRQ_REMAP
 	if (!AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir))
 		return 0;
 
@@ -872,10 +871,8 @@ static int iommu_init_ga_log(struct amd_iommu *iommu)
 err_out:
 	free_ga_log(iommu);
 	return -EINVAL;
-#else
-	return 0;
-#endif /* CONFIG_IRQ_REMAP */
 }
+#endif /* CONFIG_IRQ_REMAP */
 
 static int __init alloc_cwwb_sem(struct amd_iommu *iommu)
 {