sisfb: eliminate compiler warnings

Convert some bit masks to 8-bit values to avoid the following compiler
warnings:

drivers/video/sis/sis_main.c:3858: warning: large integer implicitly truncated to unsigned type
drivers/video/sis/init301.c:5855: warning: large integer implicitly truncated to unsigned type
drivers/video/sis/init301.c:5869: warning: large integer implicitly truncated to unsigned type

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Thomas Winischhofer <thomas@winischhofer.net>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/video/sis/init301.c

@@ -5852,7 +5852,7 @@ SiS_SetGroup1_LVDS(struct SiS_Private *SiS_Pr, unsigned short ModeNo, unsigned s
      temp = tempax & 0x00FF;
      SiS_SetReg(SiS_Pr->SiS_Part1Port,0x43,temp);
      temp = ((tempax & 0xFF00) >> 8) << 3;
-     SiS_SetRegANDOR(SiS_Pr->SiS_Part1Port,0x44,~0x0F8,temp);
+     SiS_SetRegANDOR(SiS_Pr->SiS_Part1Port, 0x44, 0x07, temp);
 
      tempax = SiS_Pr->SiS_VDE;				 	/* BDxWadrst1 = BDxWadrst0 + BDxWadroff * VDE */
      if(SiS_Pr->SiS_LCDResInfo == Panel_320x240_1 ||
@@ -5866,7 +5866,7 @@ SiS_SetGroup1_LVDS(struct SiS_Private *SiS_Pr, unsigned short ModeNo, unsigned s
      temp = ((tempeax & 0xFF0000) >> 16) | 0x10;
      SiS_SetReg(SiS_Pr->SiS_Part1Port,0x40,temp);
      temp = ((tempeax & 0x01000000) >> 24) << 7;
-     SiS_SetRegANDOR(SiS_Pr->SiS_Part1Port,0x3C,~0x080,temp);
+     SiS_SetRegANDOR(SiS_Pr->SiS_Part1Port, 0x3C, 0x7F, temp);
 
      SiS_SetReg(SiS_Pr->SiS_Part1Port,0x2F,0x03);
      SiS_SetReg(SiS_Pr->SiS_Part1Port,0x03,0x50);

drivers/video/sis/sis_main.c

@@ -3855,7 +3855,7 @@ sisfb_post_setmode(struct sis_video_info *ivideo)
 			reg1 = 0x00;
 		}
 		SiS_SetRegANDOR(SISCR, ivideo->SiS_Pr.SiS_MyCR63, ~0x40, reg);
-		SiS_SetRegANDOR(SISSR, 0x1f, ~0xc0, reg1);
+		SiS_SetRegANDOR(SISSR, 0x1f, 0x3f, reg1);
 	}
 #endif