linux-next: enable PMEM (MR 6228)

PMEM aka persistent memory enables a region of memory to be treated as a
block device. This is particularly useful as a way for EFI bootloaders
to retrieve a full OS image (via HTTP) and make it accessible to the OS.

Support for this is making its way to U-Boot: https://lore.kernel.org/u-boot/20250203105912.196654-1-sughosh.ganu@linaro.org/

Let's enable this in postmarketOS so we can enable HTTP booting images
directly from postmarketOS.org.

Signed-off-by: Caleb Connolly <caleb@postmarketos.org>
[ci:skip-build]: already built successfully in CI

device/testing/linux-next/APKBUILD

@@ -3,7 +3,7 @@
 
 pkgname=linux-next
 pkgver=6.14_git20250219
-pkgrel=0
+pkgrel=1
 _nextver="${pkgver#*_git}"
 pkgdesc="Linux next kernel"
 arch="aarch64"
@@ -71,5 +71,5 @@ package() {
 sha512sums="
 febdbec2b601027a248bde095419bacc08e2839634b5aba3169de31488a223d0dcfeae6ff00bb2020b9d413ff75c7717fca1ec1e60e6c977d1ae2ed6ef6976ac  linux-next-next-20250219.tar.gz
 8de0a3791ea671528a9fc753071683dfea68ea4f4c22060fc0ca8a4b1b3d76eaa2a3fd40bb013173f0e55da15dde91cf285902779beb35781b6c90f39244ce11  devices.config
-eaceb011997e5f19ad8c5e9b4d291ebe264d83953f9b21d5b1a0c479602edb235252657f297b1a59c7a11dd2205d40360197489a3337ba6f8e040ecf2b51f527  pmos.config
+48999c505effe9be5e9394d4954691de453f01f6bf24dc9971f1d742a1c4e36133bcc4b95b82b6b1d59993ff58f53168f0019280947de6963fb4fc37c0ab1679  pmos.config
 "

device/testing/linux-next/pmos.config

@@ -231,3 +231,12 @@ CONFIG_DYNAMIC_DEBUG=y
 # Alpine uses zstd compressed firmware
 CONFIG_FW_LOADER_COMPRESS=y
 CONFIG_FW_LOADER_COMPRESS_ZSTD=y
+
+# Persistent Memory support, allows the rootfs to
+# be loaded into memory by the bootloader. Used
+# for EFI HTTP booting.
+CONFIG_ARM64_PMEM=y
+CONFIG_LIBNVDIMM=y
+CONFIG_OF_PMEM=y
+CONFIG_BLK_DEV_PMEM=y
+CONFIG_ZONE_DEVICE=y