recipes: Update LICENSE variable to use SPDX license identifiers

Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-networking/recipes-support/ncp/libowfat_0.32.bb

@@ -3,7 +3,7 @@ DESCRIPTION = "libowfat is a library of general purpose APIs extracted from Dan
 Bernstein's software (libdjb), reimplemented and covered by the GNU \
 General Public License Version 2 (no later versions)."
 HOMEPAGE = "http://www.fefe.de/libowfat"
-LICENSE = "GPLv2"
+LICENSE = "GPL-2.0-only"
 LIC_FILES_CHKSUM = "file://COPYING;md5=8ca43cbc842c2336e835926c2166c28b"
 
 SRC_URI = "https://www.fefe.de/${BPN}/${BP}.tar.xz \

meta-networking/recipes-support/ncp/ncp_1.2.4.bb

@@ -3,7 +3,7 @@ DESCRIPTION = "ncp is a utility for copying files in a LAN. It has absolutely no
 security or integrity checking, no throttling, no features, except \
 one: you don't have to type the coordinates of your peer."
 HOMEPAGE = "http://www.fefe.de/ncp"
-LICENSE = "GPLv2"
+LICENSE = "GPL-2.0-only"
 LIC_FILES_CHKSUM = "file://${COREBASE}/meta/files/common-licenses/GPL-2.0-only;md5=801f80980d171dd6425610833a22dbe6"
 DEPENDS = "libowfat"