intel/skylake: HAVE_UART_MEMORY_MAPPED doesn't exist anymore

... the configuration is handled further below in the file by virtue of
select DRIVERS_UART_8250MEM

Change-Id: Ie5481d23cd3ac3561958fd100bd05c0e4b03ce00
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/11612
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)

src/soc/intel/skylake/Kconfig

@@ -24,7 +24,6 @@ config CPU_SPECIFIC_OPTIONS
 	select HAVE_HARD_RESET
 	select HAVE_MONOTONIC_TIMER
 	select HAVE_SMI_HANDLER
-	select HAVE_UART_MEMORY_MAPPED
 	select IOAPIC
 	select MMCONF_SUPPORT
 	select MMCONF_SUPPORT_DEFAULT