spi: zynq: missing break statement

There is a missing break statement here so selecting both only selects
upper.

Fixes: dfe11a11d523 ('spi: Add support for Zynq Ultrascale+ MPSoC GQSPI controller')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-zynqmp-gqspi.c

@@ -214,6 +214,7 @@ static void zynqmp_gqspi_selectslave(struct zynqmp_qspi *instanceptr,
 	case GQSPI_SELECT_FLASH_CS_BOTH:
 		instanceptr->genfifocs = GQSPI_GENFIFO_CS_LOWER |
 			GQSPI_GENFIFO_CS_UPPER;
+		break;
 	case GQSPI_SELECT_FLASH_CS_UPPER:
 		instanceptr->genfifocs = GQSPI_GENFIFO_CS_UPPER;
 		break;