[rpm] Add XATTR as enabled by default. Contributes to JB#30370

Extended attributes are needed for cp to be able to copy rootfs
as it originally is. Enable CONFIG_XATTR.

Signed-off-by: Kalle Jokiniemi <kalle.jokiniemi@jolla.com>

rpm/busybox-static.config

@@ -1011,3 +1011,5 @@ CONFIG_FEATURE_LOGREAD_REDUCED_LOCKING=y
 CONFIG_KLOGD=y
 CONFIG_FEATURE_KLOGD_KLOGCTL=y
 CONFIG_LOGGER=y
+
+CONFIG_XATTR=y