Remove systemd locale patch from our buildroot

For some time we patched systemd in buildroot (d75c2f9: "systemd: fix
locale"). We used locale en_US.UTF-8 instead of default C.UTF-8
because there were some issues with glibc not supporting C.UTF-8[1].

But it seems that the patch is no longer necessary [1] since glibc 2.35
which is (fortunately) within our toolchain.

This patch reverts the systemd default locale to C.UTF-8 and reverts
changes done by d75c2f9.

[1] https://github.com/systemd/systemd/issues/11259

Bug: https://github.com/systemd/systemd/issues/11259
Fixes: d75c2f914fe219aa46c9a599ec28bc13e91052ae
Change-Id: I1730c57ad278e53fa0f79b21bf3a4816c37eb1f3
diff --git a/configs/czechlight_clearfog_defconfig b/configs/czechlight_clearfog_defconfig
index 37e5a12..d36f71b 100644
--- a/configs/czechlight_clearfog_defconfig
+++ b/configs/czechlight_clearfog_defconfig
@@ -19,8 +19,6 @@
 BR2_TARGET_GENERIC_GETTY_PORT="ttyS0"
 BR2_TARGET_GENERIC_GETTY_BAUDRATE_115200=y
 # BR2_TARGET_GENERIC_REMOUNT_ROOTFS_RW is not set
-BR2_ENABLE_LOCALE_WHITELIST="C en_US C.UTF-8 en_US.UTF-8"
-BR2_GENERATE_LOCALE="en_US.UTF-8"
 BR2_ROOTFS_USERS_TABLES="$(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/common/users"
 BR2_ROOTFS_OVERLAY="$(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/common/overlay/ $(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/clearfog/overlay/"
 BR2_ROOTFS_POST_BUILD_SCRIPT="$(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/clearfog/post_build.sh"
diff --git a/submodules/buildroot b/submodules/buildroot
index 09b6443..92042c2 160000
--- a/submodules/buildroot
+++ b/submodules/buildroot
@@ -1 +1 @@
-Subproject commit 09b6443ee92e6d9f7597e1cfa45686a16759fac5
+Subproject commit 92042c21cb58cc7e7e2bb6a05e473cf439f7557b