drivers/pc80/mc146818rtc: Remove read_option_lowlevel()

This was a workaround for romcc.

Change-Id: I34f41390afbd88f3ace7003fd18c2edd56712a67
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37954
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/include/pc80/mc146818rtc.h

@@ -185,14 +185,9 @@ int cmos_chksum_valid(void);
 
 enum cb_err set_option(const char *name, void *val);
 enum cb_err get_option(void *dest, const char *name);
-unsigned int read_option_lowlevel(unsigned int start, unsigned int size,
-	unsigned int def);
 
 int do_normal_boot(void);
 
-#define read_option(name, default) read_option_lowlevel(CMOS_VSTART_ ##name, \
-	CMOS_VLEN_ ##name, (default))
-
 #if CONFIG(CMOS_POST)
 #if CONFIG(USE_OPTION_TABLE)
 # include "option_table.h"