uart: Do not guard entire include file by config options

Do not guard the file by CONFIG_CONSOLE_SERIAL8250 or
CONFIG_CONSOLE_SERIAL8250MEM or CONFIG_CONSOLE_SERIAL.

Don't do indirect includes for <uart8250.h>.

The config-specific options are already properly guarded, and there
is no need to guard the register and bit definitions.

Change-Id: I7528b18cdc62bc5c22486f037e14002838a2176e
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/4585
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/lib/uart8250.c

@@ -19,6 +19,7 @@
  */
 
 #include <arch/io.h>
+#include <uart.h>
 #include <uart8250.h>
 #include <pc80/mc146818rtc.h>
 #include <trace.h>

src/lib/uart8250mem.c

@@ -19,6 +19,7 @@
  */
 
 #include <arch/io.h>
+#include <uart.h>
 #include <uart8250.h>
 #include <pc80/mc146818rtc.h>
 #if CONFIG_USE_OPTION_TABLE