main/lk2nd: upgrade to 0.15.0 (MR 4423)

[ci:skip-build] already built successfully in CI

main/lk2nd/APKBUILD

 # Maintainer: Alexey Minnekhanov <alexeymin@postmarketos.org>
 pkgname=lk2nd
-pkgver=0.14.0
-pkgrel=1
+pkgver=0.15.0
+pkgrel=0
 pkgdesc="Secondary little kernel (lk) bootloader for several Qualcomm devices"
 arch="armv7 aarch64"
 url="https://github.com/msm8916-mainline/lk2nd"
@@ -90,5 +90,5 @@ msm8226_appended() {
 }
 
 sha512sums="
-6673b0f060e95430e03e146281f58165fa2093b9b7c448efcf2d3add16909425278ecb89c44c3adf5aeede54e186d9b1514bf9a7796b1ff701faf26a82502be9  lk2nd-0.14.0.tar.gz
+60551065ea072257b459629ea2c555933fae97eef08e6bee5904aa3751cb67fa38125f89f8d7e06c6d9438b3783d81da428b3b428e46cf6bd8dae0ee9163c1b5  lk2nd-0.15.0.tar.gz
 "