src: Retype option API to use unsigned integers

The CMOS option system does not support negative integers. Thus, retype
and rename the option API functions to reflect this.

Change-Id: Id3480e5cfc0ec90674def7ef0919e0b7ac5b19b3
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/52672
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by:  Felix Singer <felixsinger@posteo.net>

src/soc/intel/broadwell/pch/lpc.c

@@ -132,7 +132,7 @@ static void pch_power_options(struct device *dev)
 	 *
 	 * If the option is not existent (Laptops), use Kconfig setting.
 	 */
-	const int pwr_on = get_int_option("power_on_after_fail",
+	const unsigned int pwr_on = get_uint_option("power_on_after_fail",
 					  CONFIG_MAINBOARD_POWER_FAILURE_STATE);
 
 	reg16 = pci_read_config16(dev, GEN_PMCON_3);