spi: zynqmp_gqspi: Fix unaligned data writes issue

When unaligned 3 bytes data write operation is performed, 3rd byte
is being over written by 1st byte of 3 bytes data. This patch
fixes it.

Signed-off-by: T Karthik Reddy <t.karthik.reddy@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/drivers/spi/zynqmp_gqspi.c b/drivers/spi/zynqmp_gqspi.c
index e0e6687..a56e8b2 100644
--- a/drivers/spi/zynqmp_gqspi.c
+++ b/drivers/spi/zynqmp_gqspi.c
@@ -429,10 +429,8 @@
 				data |= GENMASK(31, 16);
 				break;
 			case 3:
-				data = *((u16 *)buf);
-				buf += 2;
-				data |= (*((u8 *)buf) << 16);
-				buf += 1;
+				data = *buf;
+				buf += 3;
 				data |= GENMASK(31, 24);
 				break;
 			}