intel_th: Constify all drvdata references

Anything that deals with drvdata structures should leave them intact.
Reflect this in function signatures.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210414171251.14672-4-alexander.shishkin@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/intel_th/core.c

@@ -844,7 +844,7 @@ static irqreturn_t intel_th_irq(int irq, void *data)
  * @irq:	irq number
  */
 struct intel_th *
-intel_th_alloc(struct device *dev, struct intel_th_drvdata *drvdata,
+intel_th_alloc(struct device *dev, const struct intel_th_drvdata *drvdata,
 	       struct resource *devres, unsigned int ndevres)
 {
 	int err, r, nr_mmios = 0;

drivers/hwtracing/intel_th/intel_th.h

@@ -74,7 +74,7 @@ struct intel_th_drvdata {
  */
 struct intel_th_device {
 	struct device		dev;
-	struct intel_th_drvdata *drvdata;
+	const struct intel_th_drvdata *drvdata;
 	struct resource		*resource;
 	unsigned int		num_resources;
 	unsigned int		type;
@@ -224,7 +224,7 @@ static inline struct intel_th *to_intel_th(struct intel_th_device *thdev)
 }
 
 struct intel_th *
-intel_th_alloc(struct device *dev, struct intel_th_drvdata *drvdata,
+intel_th_alloc(struct device *dev, const struct intel_th_drvdata *drvdata,
 	       struct resource *devres, unsigned int ndevres);
 void intel_th_free(struct intel_th *th);
 
@@ -272,7 +272,7 @@ struct intel_th {
 
 	struct intel_th_device	*thdev[TH_SUBDEVICE_MAX];
 	struct intel_th_device	*hub;
-	struct intel_th_drvdata	*drvdata;
+	const struct intel_th_drvdata	*drvdata;
 
 	struct resource		resource[TH_MMIO_END];
 	int			(*activate)(struct intel_th *);

drivers/hwtracing/intel_th/pci.c

@@ -71,7 +71,7 @@ static void intel_th_pci_deactivate(struct intel_th *th)
 static int intel_th_pci_probe(struct pci_dev *pdev,
 			      const struct pci_device_id *id)
 {
-	struct intel_th_drvdata *drvdata = (void *)id->driver_data;
+	const struct intel_th_drvdata *drvdata = (void *)id->driver_data;
 	struct resource resource[TH_MMIO_END + TH_NVEC_MAX] = {
 		[TH_MMIO_CONFIG]	= pdev->resource[TH_PCI_CONFIG_BAR],
 		[TH_MMIO_SW]		= pdev->resource[TH_PCI_STH_SW_BAR],