i2c: amd-mp2: Remove useless DMA-32 fallback configuration

As stated in [1], dma_set_mask() with a 64-bit mask never fails if
dev->dma_mask is non-NULL. So, if it fails, the 32 bits case will also
fail for the same reason.

Simplify code and remove some dead code accordingly.

[1]: https://lkml.org/lkml/2021/6/7/398Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Nehal Bakulchandra Shah <Nehal-bakulchandra.Shah@amd.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/busses/i2c-amd-mp2-pci.c

@@ -308,11 +308,8 @@ static int amd_mp2_pci_init(struct amd_mp2_dev *privdata,
 	pci_set_master(pci_dev);
 
 	rc = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(64));
-	if (rc) {
-		rc = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(32));
 	if (rc)
 		goto err_dma_mask;
-	}
 
 	/* Set up intx irq */
 	writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);