kernel: generic: 5.4: fix mips command line parameter patch

Fixing a build error when CONFIG_KERNEL_KEXEC is enabled:

make[5]: Entering directory '/home/bjorn/tmp/tmp-lede/build_dir/target-mipsel_24kc_musl/linux-ramips_mt7621/linux-5.4.28'
  CALL    scripts/checksyscalls.sh
  CALL    scripts/atomic/check-atomics.sh
  CHK     include/generated/compile.h
  CC      arch/mips/kernel/machine_kexec.o
arch/mips/kernel/machine_kexec.c: In function 'kexec_nonboot_cpu_jump':
arch/mips/kernel/machine_kexec.c:268:27: error: 'relocate_new_kernel_size' undeclared (first use in this function); did you mean 'kexec_relocate_new_kernel_end'?
      reboot_code_buffer + relocate_new_kernel_size);
                           ^~~~~~~~~~~~~~~~~~~~~~~~
                           kexec_relocate_new_kernel_end
arch/mips/kernel/machine_kexec.c:268:27: note: each undeclared identifier is reported only once for each function it appears in
arch/mips/kernel/machine_kexec.c: In function 'kexec_reboot':
arch/mips/kernel/machine_kexec.c:306:27: error: 'relocate_new_kernel_size' undeclared (first use in this function); did you mean 'kexec_relocate_new_kernel_end'?
      reboot_code_buffer + relocate_new_kernel_size);
                           ^~~~~~~~~~~~~~~~~~~~~~~~
                           kexec_relocate_new_kernel_end
make[7]: *** [scripts/Makefile.build:266: arch/mips/kernel/machine_kexec.o] Error 1

Signed-off-by: Bjørn Mork <bjorn@mork.no>

target/linux/generic/pending-5.4/330-MIPS-kexec-Accept-command-line-parameters-from-users.patch

@@ -150,6 +150,24 @@ Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>
  
  	if (_machine_kexec_prepare)
  		return _machine_kexec_prepare(kimage);
+@@ -161,7 +265,7 @@ machine_crash_shutdown(struct pt_regs *r
+ void kexec_nonboot_cpu_jump(void)
+ {
+ 	local_flush_icache_range((unsigned long)relocated_kexec_smp_wait,
+-				 reboot_code_buffer + relocate_new_kernel_size);
++				 reboot_code_buffer + KEXEC_RELOCATE_NEW_KERNEL_SIZE);
+ 
+ 	relocated_kexec_smp_wait(NULL);
+ }
+@@ -199,7 +303,7 @@ void kexec_reboot(void)
+ 	 * machine_kexec() CPU.
+ 	 */
+ 	local_flush_icache_range(reboot_code_buffer,
+-				 reboot_code_buffer + relocate_new_kernel_size);
++				 reboot_code_buffer + KEXEC_RELOCATE_NEW_KERNEL_SIZE);
+ 
+ 	do_kexec = (void *)reboot_code_buffer;
+ 	do_kexec();
 @@ -212,10 +316,12 @@ machine_kexec(struct kimage *image)
  	unsigned long *ptr;