[U-Boot] Bug in cfb_console driver

Hello,

commit 03d31fcf4c37d90a00e66f06b38742960139f090 break video framebuffer output on Nokia N900. After this commit is video output garbaged and not readable on display. Problem is in function video_invertchar() - when I commented it, video output is OK, but without cursor. Problem is only on real N900 device, not in qemu.