RISC-V: avoid soft lockup Radeon GPUs with u-boot-menu

For the SiFive HiFive Unmatched board we create a pre-installed image using
u-boot-menu. Increase the watchdog threshold in this case too.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

live-build/ubuntu-cpc/hooks.d/base/disk-image-uefi.binary

@@ -370,6 +370,8 @@ EOF
                     *)
                         cp ${my_d}/riscv64/grub/90_watchdog-thresh.cfg mountpoint/etc/default/grub.d/
                         chroot mountpoint apt-get install -qqy u-boot-menu #grub-efi-riscv64
+                        mkdir -p mountpoint/etc/u-boot-menu/conf.d/
+                        cp ${my_d}/riscv64/u-boot-menu/*.conf mountpoint/etc/u-boot-menu/conf.d/
                         efi_target=riscv64-efi
                         chroot mountpoint u-boot-update
                         u_boot_arch="${SUBARCH}"

live-build/ubuntu-cpc/hooks.d/base/riscv64/u-boot-menu/10_cmdline.conf

@@ -0,0 +1 @@
+U_BOOT_PARAMETERS="ro efi=debug earlycon"

live-build/ubuntu-cpc/hooks.d/base/riscv64/u-boot-menu/90_watchdog-thresh.conf

@@ -0,0 +1,3 @@
+# When booting with Radeon GPUs a soft lockup was observed. Increase the
+# watchdog threshhold.
+U_BOOT_PARAMETERS="$U_BOOT_PARAMETERS sysctl.kernel.watchdog_thresh=60"