platform/x86/intel/pmc: Add suspend callback

Add a suspend callback to struct pmc for performing platform specific tasks
before device suspend. This is needed in order to perform GBE LTR ignore on
certain platforms at suspend-time instead of at probe-time and replace the
GBE LTR ignore removal that was done in order to fix a bug introduced by
commit 8049512 ("platform/x86:intel/pmc: Combine core_init() and
core_configure()").

Fixes: 8049512 ("platform/x86:intel/pmc: Combine core_init() and core_configure()")
Signed-off-by: "David E. Box" <david.e.box@linux.intel.com>
Link: https://lore.kernel.org/r/20231223032548.1680738-4-david.e.box@linux.intel.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

drivers/platform/x86/intel/pmc/core.c

@@ -1279,6 +1279,9 @@ static __maybe_unused int pmc_core_suspend(struct device *dev)
 	struct pmc_dev *pmcdev = dev_get_drvdata(dev);
 	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
 
+	if (pmcdev->suspend)
+		pmcdev->suspend(pmcdev);
+
 	/* Check if the syspend will actually use S0ix */
 	if (pm_suspend_via_firmware())
 		return 0;

drivers/platform/x86/intel/pmc/core.h

@@ -363,6 +363,7 @@ struct pmc {
  * @s0ix_counter:	S0ix residency (step adjusted)
  * @num_lpm_modes:	Count of enabled modes
  * @lpm_en_modes:	Array of enabled modes from lowest to highest priority
+ * @suspend:		Function to perform platform specific suspend
  * @resume:		Function to perform platform specific resume
  *
  * pmc_dev contains info about power management controller device.
@@ -379,6 +380,7 @@ struct pmc_dev {
 	u64 s0ix_counter;
 	int num_lpm_modes;
 	int lpm_en_modes[LPM_MAX_NUM_MODES];
+	void (*suspend)(struct pmc_dev *pmcdev);
 	int (*resume)(struct pmc_dev *pmcdev);
 
 	bool has_die_c6;