disk: Use BOOT_DEFAULTS instead of DISTRO_DEFAULTS

Set default y based on common BOOT_DEFAULTS instead of DISTRO_DEFAULTS.

No change is intended, affected options is already implied for DISTRO
and BOOTSTD due to BOOT_DEFAULTS imply DOS_PARTITION (USB_STORAGE),
EFI_PARTITION and ISO_PARTITION.

Fixes: a0c739c1 ("boot: Create a common BOOT_DEFAULTS for distro and bootstd")
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Simon Glass <sjg@chromium.org>