clk: socfpga: switch to GENMASK()

Convert the code to use GENMASK() helper instead of div_mask() macro.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
diff --git a/drivers/clk/socfpga/clk-periph-a10.c b/drivers/clk/socfpga/clk-periph-a10.c
index 64f93ac..1f397cb 100644
--- a/drivers/clk/socfpga/clk-periph-a10.c
+++ b/drivers/clk/socfpga/clk-periph-a10.c
@@ -38,7 +38,7 @@
 		div = socfpgaclk->fixed_div;
 	} else if (socfpgaclk->div_reg) {
 		div = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
-		div &= div_mask(socfpgaclk->width);
+		div &= GENMASK(socfpgaclk->width - 1, 0);
 		div += 1;
 	} else {
 		div = ((readl(socfpgaclk->hw.reg) & 0x7ff) + 1);