stmmac: intel: Add a missing clk_disable_unprepare() call in intel_eth_pci_remove()

Commit 09f012e6 ("stmmac: intel: Fix clock handling on error and remove
paths") removed this clk_disable_unprepare()

This was partly revert by commit ac322f86 ("net: stmmac: Fix clock
handling on remove path") which removed this clk_disable_unprepare()
because:
"
   While unloading the dwmac-intel driver, clk_disable_unprepare() is
   being called twice in stmmac_dvr_remove() and
   intel_eth_pci_remove(). This causes kernel panic on the second call.
"

However later on, commit 5ec55823 ("net: stmmac: add clocks management
for gmac driver") has updated stmmac_dvr_remove() which do not call
clk_disable_unprepare() anymore.

So this call should now be called from intel_eth_pci_remove().

Fixes: 5ec55823 ("net: stmmac: add clocks management for gmac driver")
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/d7c8c1dadf40df3a7c9e643f76ffadd0ccc1ad1b.1660659689.git.christophe.jaillet@wanadoo.frSigned-off-by: NJakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/stmicro/stmmac/dwmac-intel.c

@@ -1134,6 +1134,7 @@ static void intel_eth_pci_remove(struct pci_dev *pdev)
 
 	stmmac_dvr_remove(&pdev->dev);
 
+	clk_disable_unprepare(priv->plat->stmmac_clk);
 	clk_unregister_fixed_rate(priv->plat->stmmac_clk);
 
 	pcim_iounmap_regions(pdev, BIT(0));