boot: serial recovery: Add pca10090 default detect pin
boot: serial recovery: Add pca10090 default detect pin

Add button 1 as default serial detect pin for nrf9160_pca10090

Signed-off-by: Andreas Vibeto <e5b5c81871b266ee79ddfe5a473cc66a97fb9ca3@nordicsemi.no>
utzig/mcuboot,tamban01/mcuboot,runtimeco/mcuboot,ATmobica/mcuboot,runtimeco/mcuboot,utzig/mcuboot,utzig/mcuboot,runtimeco/mcuboot,tamban01/mcuboot,tamban01/mcuboot,tamban01/mcuboot,runtimeco/mcuboot,ATmobica/mcuboot,ATmobica/mcuboot,utzig/mcuboot,ATmobica/mcuboot,ATmobica/mcuboot,tamban01/mcuboot,runtimeco/mcuboot,utzig/mcuboot