fbdev: atyfb: Remove unused clock determination

Just below the removed lines par->clk_wr_offset is hard coded to 3 so
there is no use in determining a different clock just to then ignore it
anyway. This also removes the only I/O port use remaining in the driver
allowing it to be built without CONFIG_HAS_IOPORT.

Link: https://lore.kernel.org/all/ZBx5aLo5h546BzBt@intel.com/Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Helge Deller <deller@gmx.de>

drivers/video/fbdev/aty/atyfb_base.c

@@ -3498,11 +3498,6 @@ static int atyfb_setup_generic(struct pci_dev *pdev, struct fb_info *info,
 	if (ret)
 		goto atyfb_setup_generic_fail;
 #endif
-	if (!(aty_ld_le32(CRTC_GEN_CNTL, par) & CRTC_EXT_DISP_EN))
-		par->clk_wr_offset = (inb(R_GENMO) & 0x0CU) >> 2;
-	else
-		par->clk_wr_offset = aty_ld_8(CLOCK_CNTL, par) & 0x03U;
-
 	/* according to ATI, we should use clock 3 for acelerated mode */
 	par->clk_wr_offset = 3;