enable CONFIG_SECCOMP to fix flatpak

enable CONFIG_SECCOMP in the kernel to fix

bwrap: prctl(PR_SET_SECCOMP): Invalid argument
bwrap: prctl(PR_SET_SECCOMP): Invalid argument

when running a flatpak

main/linux-postmarketos-qcom-msm8974/APKBUILD

@@ -4,7 +4,7 @@ _config="config-$_flavor.$CARCH"
 pkgname=linux-$_flavor
 
 pkgver=5.6.0_rc6
-pkgrel=2
+pkgrel=3
 
 arch="armv7"
 pkgdesc="Kernel close to mainline with extra patches for Qualcomm MSM8974 devices"
@@ -158,4 +158,4 @@ dev() {
 }
 
 sha512sums="92866a037fd1bd3b17572754548c19423f6e762d90fb1ebca52c252ace85c87b6f747515f8606fe627d34c59828cbebf83054b9d6e5dd977e0398d9c46fcc176  linux-postmarketos-b9f39bdf61e5c8f5db63afe7ab1c9ff77aa6b4bc.tar.gz
-1b0d879dfa603bfc5775e75442b7d5374ee34445c71abf0ebbdbb6af6f31a0709e59ae1f6a723fd7af79086c88588a62b4d10bd2320fd5b767fd235b9d815e6d  config-postmarketos-qcom-msm8974.armv7"
+a4e98e627d41d7aeb802ebff4e7a1ce34e52fc5a05a2c736d65deacffbc30823c96cb7f3880d5357b7e3c51b08cfa6f1e3e73801d1f0ac273004cae155381fa1  config-postmarketos-qcom-msm8974.armv7"