[coreboot] [PATCH] libpayload: serial output 8 bit clean

[Ulf Jordan]

The attached patch makes the serial output function serial_putchar() 8 bit 
clean. The motivation for this is that the low level driver should not 
modify the data in unexpected ways. Furthermore translate_special_chars() 
is removed, since that functionality is now provided by the ACS machinery 
in tinycurses.

Compile and runtime tested with coreinfo+libpayload+coreboot-v3 under 
QEMU.

/ulf