staging: sm750fb: Prefer using the BIT macro

Challenge suggested by coccinelle.

Replace bit shifting on 1 with the BIT(x) macro.
Coccinelle script:

@@
constant c;
@@

-(1 << c)
+BIT(c)
Signed-off-by: Sanjana Sanikommu <sanjana99reddy99@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/sm750fb/ddk750_chip.c

@@ -45,7 +45,7 @@ static unsigned int get_mxclk_freq(void)
 	OD = (pll_reg & PLL_CTRL_OD_MASK) >> PLL_CTRL_OD_SHIFT;
 	POD = (pll_reg & PLL_CTRL_POD_MASK) >> PLL_CTRL_POD_SHIFT;
 
-	return DEFAULT_INPUT_CLOCK * M / N / (1 << OD) / (1 << POD);
+	return DEFAULT_INPUT_CLOCK * M / N / BIT(OD) / BIT(POD);
 }
 
 /*