ptp_pch: Remove unused function 'pch_ch_control_read()'

Fixes the following W=1 kernel build warning(s):

 drivers/ptp/ptp_pch.c:182:5: warning: no previous prototype for ‘pch_ch_control_read’ [-Wmissing-prototypes]

Cc: Richard Cochran <richardcochran@gmail.com> (maintainer:PTP HARDWARE CLOCK SUPPORT)
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Flavio Suligoi <f.suligoi@asem.it>
Cc: netdev@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe.h

@@ -612,7 +612,6 @@ void pch_gbe_free_tx_resources(struct pch_gbe_adapter *adapter,
 void pch_gbe_free_rx_resources(struct pch_gbe_adapter *adapter,
 			       struct pch_gbe_rx_ring *rx_ring);
 void pch_gbe_update_stats(struct pch_gbe_adapter *adapter);
-u32 pch_ch_control_read(struct pci_dev *pdev);
 void pch_ch_control_write(struct pci_dev *pdev, u32 val);
 u32 pch_ch_event_read(struct pci_dev *pdev);
 void pch_ch_event_write(struct pci_dev *pdev, u32 val);

drivers/ptp/ptp_pch.c

@@ -179,17 +179,6 @@ static inline void pch_block_reset(struct pch_dev *chip)
 	iowrite32(val, (&chip->regs->control));
 }
 
-u32 pch_ch_control_read(struct pci_dev *pdev)
-{
-	struct pch_dev *chip = pci_get_drvdata(pdev);
-	u32 val;
-
-	val = ioread32(&chip->regs->ch_control);
-
-	return val;
-}
-EXPORT_SYMBOL(pch_ch_control_read);
-
 void pch_ch_control_write(struct pci_dev *pdev, u32 val)
 {
 	struct pch_dev *chip = pci_get_drvdata(pdev);