spi: cadence: fix static checker warning

This patch fixes Smatch static checker warning.
CDNS_XSPI_CMD_REG_5 is used in ACMD mode and currently
only STIG mode is enabled which doesn't use CDNS_XSPI_CMD_REG_5
and hence everything was working in STIG mode.
Since plan is to use same function cdns_xspi_trigger_command()
in ACMD mode, increasing size of the array passed to it.

Fixes: a16cc807 ("spi: cadence: add support for Cadence XSPI controller")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/linux-spi/20210930134231.GA14363@kili/Signed-off-by: Parshuram Thombare <pthombar@cadence.com>
Link: https://lore.kernel.org/r/1633336704-22735-1-git-send-email-pthombar@cadence.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-cadence-xspi.c

@@ -239,7 +239,7 @@ static int cdns_xspi_wait_for_controller_idle(struct cdns_xspi_dev *cdns_xspi)
 }
 
 static void cdns_xspi_trigger_command(struct cdns_xspi_dev *cdns_xspi,
-				      u32 cmd_regs[5])
+				      u32 cmd_regs[6])
 {
 	writel(cmd_regs[5], cdns_xspi->iobase + CDNS_XSPI_CMD_REG_5);
 	writel(cmd_regs[4], cdns_xspi->iobase + CDNS_XSPI_CMD_REG_4);
@@ -346,7 +346,7 @@ static int cdns_xspi_send_stig_command(struct cdns_xspi_dev *cdns_xspi,
 				       const struct spi_mem_op *op,
 				       bool data_phase)
 {
-	u32 cmd_regs[5];
+	u32 cmd_regs[6];
 	u32 cmd_status;
 	int ret;