Upgrade kernel to 4.14.341-openela

This is a continuation of the 4.14 series by the Open Enterprise Linux
Alliance, ostensibly to the same maintenance standards as the now
discontinued kernel.org LTS.

This code is primarily offered as a Git repository, with gz tarballs
also available, but no xz versions. Switching back to a gzipped version
of the kernel source code would introduce too much srcfs growth, so we
use the last kernel.org tar.xz release (4.14.336), and apply OpenELA's
changes using a patch generated from the Git repository.

steps/linux-4.14.336/patches/remove-alternative-asm.patch

@@ -1,34 +0,0 @@
-SPDX-FileCopyrightText: 2021 fosslinux <fosslinux@aussies.space>
-
-SPDX-License-Identifier: GPL-2.0-only
-
-Our older version of binutils doesn't play very nicely with binutils for a
-couple of edgecase macros. It seems that ALTERNATIVE is one of these. As we
-know what your system will be (not Xen), we can manually evaluate and write
-out the ALTERNATIVEs.
-
---- arch/x86/entry/entry_32.S	2021-07-31 11:40:07.458032771 +1000
-+++ arch/x86/entry/entry_32.S	2021-07-31 11:40:42.835298841 +1000
-@@ -412,9 +412,8 @@
- 
- 	movl	%esp, %eax
- 	call	do_fast_syscall_32
--	/* XEN PV guests always use IRET path */
--	ALTERNATIVE "testl %eax, %eax; jz .Lsyscall_32_done", \
--		    "jmp .Lsyscall_32_done", X86_FEATURE_XENPV
-+	testl %eax, %eax
-+	jz .Lsyscall_32_done
- 
- /* Opportunistic SYSEXIT */
- 	TRACE_IRQS_ON			/* User mode traces as IRQs on. */
---- arch/x86/entry/vdso/vdso32/system_call.S	2021-07-31 11:41:40.379731622 +1000
-+++ arch/x86/entry/vdso/vdso32/system_call.S	2021-07-31 11:43:40.294633506 +1000
-@@ -55,8 +55,6 @@
- 	/* If SYSENTER (Intel) or SYSCALL32 (AMD) is available, use it. */
- 	ALTERNATIVE_2 "", SYSENTER_SEQUENCE, X86_FEATURE_SYSENTER32, \
- 	                  SYSCALL_SEQUENCE,  X86_FEATURE_SYSCALL32
--#else
--	ALTERNATIVE "", SYSENTER_SEQUENCE, X86_FEATURE_SEP
- #endif
- 
- 	/* Enter using int $0x80 */