console: rework log level to not be reliant on ROMSTAGE_CONST

The console log level variable doesn't really rely on ROMSTAGE_CONST
proper. Instead, the mutability of the variable is based on the current
implementation of ROMSTAGE_CONST (__PRE_RAM__). As such directly
use that logic for the code. In addition, refactor the code to let
the compiler and linker optimize out accesses instead of using
the pre-processor.

Change-Id: I44bcc409266ef52b9be29f75efde73a6707a53f4
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/19438
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
1 file changed