qualcomm/ipq806x: Fix uart in verstage

An old Kconfig symbol from Chrome OS survived into the Makefile (but is
nowhere declared or used). Use the same symbol as for uart.c in the other
stages.

Change-Id: I7a6f1b82254e888d6f2d65d6cff87c4d546ec097
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/10703
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

src/soc/qualcomm/ipq806x/Makefile.inc

@@ -32,7 +32,7 @@ libverstage-y += i2c.c
 libverstage-y += qup.c
 libverstage-y += spi.c
 verstage-y += timer.c
-verstage-$(CONFIG_CONSOLE_SERIAL_IPQ806X) += uart.c
+verstage-$(CONFIG_DRIVERS_UART) += uart.c
 
 romstage-y += clock.c
 romstage-y += blobs_init.c