spi: tegra: Use DIV_ROUND_UP instead of open coded

This also makes the intention more clear.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/spi-tegra114.c

@@ -267,7 +267,7 @@ static unsigned tegra_spi_calculate_curr_xfer_param(
 	unsigned max_len;
 	unsigned total_fifo_words;
 
-	tspi->bytes_per_word = (bits_per_word - 1) / 8 + 1;
+	tspi->bytes_per_word = DIV_ROUND_UP(bits_per_word, 8);
 
 	if (bits_per_word == 8 || bits_per_word == 16) {
 		tspi->is_packed = 1;

drivers/spi/spi-tegra20-sflash.c

@@ -173,7 +173,7 @@ static unsigned tegra_sflash_calculate_curr_xfer_param(
 	unsigned remain_len = t->len - tsd->cur_pos;
 	unsigned max_word;
 
-	tsd->bytes_per_word = (t->bits_per_word - 1) / 8 + 1;
+	tsd->bytes_per_word = DIV_ROUND_UP(t->bits_per_word, 8);
 	max_word = remain_len / tsd->bytes_per_word;
 	if (max_word > SPI_FIFO_DEPTH)
 		max_word = SPI_FIFO_DEPTH;

drivers/spi/spi-tegra20-slink.c

@@ -283,7 +283,7 @@ static unsigned tegra_slink_calculate_curr_xfer_param(
 	unsigned total_fifo_words;
 
 	bits_per_word = t->bits_per_word;
-	tspi->bytes_per_word = (bits_per_word - 1) / 8 + 1;
+	tspi->bytes_per_word = DIV_ROUND_UP(bits_per_word, 8);
 
 	if (bits_per_word == 8 || bits_per_word == 16) {
 		tspi->is_packed = 1;