spi: use new `spi_transfer_delay_exec` helper where straightforward

For many places in the spi drivers, using the new `spi_transfer_delay`
helper is straightforward.
It's just replacing:
```
  if (t->delay_usecs)
     udelay(t->delay_usecs);
```
with `spi_transfer_delay(t)` which handles both `delay_usecs` and the new
`delay` field.

This change replaces in all places (in the spi drivers)  where this change
is simple.

Signed-off-by: Alexandru Ardelean <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mark Brown <[email protected]>
diff --git a/drivers/spi/spi-cavium.c b/drivers/spi/spi-cavium.c
index 5aaf215..6854c3c 100644
--- a/drivers/spi/spi-cavium.c
+++ b/drivers/spi/spi-cavium.c
@@ -119,8 +119,7 @@ static int octeon_spi_do_transfer(struct octeon_spi *p,
 			*rx_buf++ = (u8)v;
 		}
 
-	if (xfer->delay_usecs)
-		udelay(xfer->delay_usecs);
+	spi_transfer_delay_exec(xfer);
 
 	return xfer->len;
 }