fbdev: imxfb: replace some magic numbers with constants

The patch gets rid of magic numbers replacing them with appropriate
macros.
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Helge Deller <deller@gmx.de>

drivers/video/fbdev/imxfb.c

@@ -89,6 +89,7 @@ struct imx_fb_videomode {
 #define PCR_BPIX_12	4
 #define PCR_BPIX_16	5
 #define PCR_BPIX_18	6
+#define PCR_PCD_MASK	GENMASK(5, 0)
 
 #define LCDC_HCR	0x1C
 #define HCR_H_WIDTH_MASK	GENMASK(31, 26)
@@ -414,8 +415,8 @@ static int imxfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
 
 	pcr = (unsigned int)tmp;
 
-	if (--pcr > 0x3F) {
-		pcr = 0x3F;
+	if (--pcr > PCR_PCD_MASK) {
+		pcr = PCR_PCD_MASK;
 		printk(KERN_WARNING "Must limit pixel clock to %luHz\n",
 				lcd_clk / pcr);
 	}
@@ -444,7 +445,7 @@ static int imxfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
 	}
 
 	/* add sync polarities */
-	pcr |= imxfb_mode->pcr & ~(0x3f | (7 << 25));
+	pcr |= imxfb_mode->pcr & ~(PCR_PCD_MASK | PCR_BPIX_MASK);
 
 	fbi->pcr = pcr;
 	/*