spi: zynqmp_gqspi: do not round immediate_data field

Immediate_data is 8 bit value in generic FIFO command. When fields data_xfer=1
and exponent=0 this field specifies the absolute number of data bytes to read
into the RXFIFO. Values from range 0xfd to 0xff are rounded up to 0x100. It
causes overwriting the next bit field which is data_xfer. According to Zynq US+
TRM only DMA transfers should be word aligned. So there is no reason to round
up the immediate_data field.

drivers/spi/zynqmp_gqspi.c

@@ -758,11 +758,6 @@ static int zynqmp_qspi_start_dma(struct zynqmp_qspi_priv *priv,
 
 	while (priv->len) {
 		len = zynqmp_qspi_calc_exp(priv, &gen_fifo_cmd);
-		if (!(gen_fifo_cmd & GQSPI_GFIFO_EXP_MASK) &&
-		    (len % GQSPI_DMA_ALIGN)) {
-			gen_fifo_cmd &= ~GENMASK(7, 0);
-			gen_fifo_cmd |= roundup(len, GQSPI_DMA_ALIGN);
-		}
 		zynqmp_qspi_fill_gen_fifo(priv, gen_fifo_cmd);
 
 		debug("GFIFO_CMD_RX:0x%x\n", gen_fifo_cmd);