rpi-kernel: update to 5.10.52.

- document how we pick the commit to be used
- fix header installations so dkms works; based on fixes to mainline
  kernel packages

In this update, we are using the commit from
https://github.com/raspberrypi/linux/releases/tag/1.20210727

srcpkgs/rpi-kernel/template

@@ -1,16 +1,23 @@
 # Template file for 'rpi-kernel'
 #
 # We track the latest Raspberry Pi LTS kernel as that is what is used in the
-# official Raspbian distribution. This is currently 5.4:
+# official Raspbian distribution. This is currently 5.10:
 #
-#   https://www.raspberrypi.org/forums/viewtopic.php?f=29&t=269769
+# https://www.raspberrypi.org/forums/viewtopic.php?f=29&t=288234
+#
+# Commit hash is picked from latest tag [1], if appropriate, or from latest
+# "Merge remote-tracking branch 'stable/linux-5.10.y' into rpi-5.10.y" commit.
+#
+# [1] https://github.com/raspberrypi/linux/releases
+#
+# WARNING: keep all rpi*-kernel packages in sync
 
-_githash="76c49e60e742d0bebd798be972d67dd3fd007691"
+_githash="86729e78125d4f3d203457940feee8bc97b11f6c"
 _gitshort="${_githash:0:7}"
 
 pkgname=rpi-kernel
-version=5.4.83
-revision=2
+version=5.10.52
+revision=1
 archs="armv6l*"
 wrksrc="linux-${_githash}"
 hostmakedepends="perl kmod uboot-mkimage openssl-devel bc bison flex"
@@ -20,7 +27,7 @@ homepage="http://www.kernel.org"
 license="GPL-2.0-only"
 short_desc="Linux kernel for Raspberry Pi zero/1 (${version%.*} series [git ${_gitshort}])"
 distfiles="https://github.com/raspberrypi/linux/archive/${_githash}.tar.gz"
-checksum=4a98ea0d68c6e74d479789c12fc97619c872cb2607ae87a881a9491c1c3fbc35
+checksum=a25a7dfce4c2ca5bdca39ddab5e43539d9b04900b0dbefe19f4f9b053e59968c
 python_version=3
 
 _kernver="${version}_${revision}"
@@ -141,7 +148,7 @@ do_install() {
 		mkdir -p ${hdrdest}/$(dirname $file)
 		install -Dm644 $file ${hdrdest}/${file}
 	done
-	for file in $(find arch/${_arch} -name module.lds -o -name Kbuild.platforms -o -name Platform); do
+	for file in $(find arch/${_arch} scripts -name module.lds -o -name Kbuild.platforms -o -name Platform); do
 		mkdir -p ${hdrdest}/$(dirname $file)
 		install -Dm644 $file ${hdrdest}/${file}
 	done
@@ -151,7 +158,7 @@ do_install() {
 	rm -rf ${DESTDIR}/usr/lib/firmware
 
 	for i in acpi asm-generic clocksource config crypto drm generated linux \
-		math-emu media net pcmcia scsi sound trace uapi video xen; do
+		math-emu media net pcmcia scsi sound trace uapi vdso video xen; do
 		[ -d include/$i ] && cp -a include/$i ${hdrdest}/include
 	done