kdump: remove redundant DEFAULT_CRASH_KERNEL_LOW_SIZE

Remove duplicate definitions, no functional changes.

Link: https://lkml.kernel.org/r/MW4PR84MB3145459ADC7EB38BBB36955B8198A@MW4PR84MB3145.NAMPRD84.PROD.OUTLOOK.COM
Signed-off-by: Youling Tang <tangyouling@kylinos.cn>
Reported-by: Huacai Chen <chenhuacai@loongson.cn>
Acked-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: tangyouling

include/linux/crash_core.h

@@ -87,12 +87,6 @@ Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
 			  void *data, size_t data_len);
 void final_note(Elf_Word *buf);
 
-#ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
-#ifndef DEFAULT_CRASH_KERNEL_LOW_SIZE
-#define DEFAULT_CRASH_KERNEL_LOW_SIZE  (128UL << 20)
-#endif
-#endif
-
 int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
 		unsigned long long *crash_size, unsigned long long *crash_base,
 		unsigned long long *low_size, bool *high);