Bring back armel build by extending the size limit for kernel image

Extend the size limit for kernel image, from 2097080 to 2729712.
This will break a few qnap devices, but keep other armel devices
running.

Also revert two commits that disabled armel previously:
- [2ed70eb] "Add empty featuresets for armel to help abiupdate script"
- [5f62872] "(Temporarily) disable armel kernel image build"

(cherry picked from commit b0a94d07b4)

debian/changelog

@@ -1,3 +1,15 @@
+linux (4.15.11-2) UNRELEASED; urgency=medium
+
+  [ Roger Shimizu ]
+  * Bring back armel build by extending the size limit for kernel image,
+    from 2097080 to 2729712. This will break a few qnap devices,
+    but keep other armel devices running.
+    Also revert two commits that disabled armel previously:
+    - [2ed70eb] "Add empty featuresets for armel to help abiupdate script"
+    - [5f62872] "(Temporarily) disable armel kernel image build"
+
+ -- Roger Shimizu <rogershimizu@gmail.com>  Fri, 23 Mar 2018 21:10:34 +0900
+
 linux (4.15.11-1) unstable; urgency=medium
 
   * New upstream stable update:

debian/config/armel/defines

@@ -1,11 +1,7 @@
 [base]
 flavours:
- #marvell
+ marvell
 kernel-arch: arm
-featuresets:
-# empty; not building images right now
-# cf.: https://lists.debian.org/debian-release/2018/02/msg00239.html
-# none
 
 [build]
 image-file: arch/arm/boot/zImage
@@ -36,7 +32,7 @@ recommends: u-boot-tools
 # HP Media Vault mv2120: 2097152 - 8 - 64 = 2097080
 # QNAP TS-109/TS-209 & TS-409: 2097152 - 8 - 64 = 2097080
 # Buffalo Linkstation LS-WSXL/WXL/WVL (from stock kernel): 2729776 - 64 = 2729712
-check-size: 2097080
+check-size: 2729712
 check-size-with-dtb: true
 ## Maximum uncompressed kernel size for supported devices
 # Buffalo Linkstation LS-WSXL/WXL/WVL: 7340032

debian/installer/armel/kernel-versions

@@ -1,2 +1,2 @@
 # arch version flavour   installedname suffix build-depends
-#armel  -       marvell   -             y      -
+armel  -       marvell   -             y      -