MIPS: fix duplicate definitions for exported symbols

[ Upstream commit 612d8078 ]

Building with clang-14 fails with:

AS      arch/mips/kernel/relocate_kernel.o
<unknown>:0: error: symbol 'kexec_args' is already defined
<unknown>:0: error: symbol 'secondary_kexec_args' is already defined
<unknown>:0: error: symbol 'kexec_start_address' is already defined
<unknown>:0: error: symbol 'kexec_indirection_page' is already defined
<unknown>:0: error: symbol 'relocate_new_kernel_size' is already defined

It turns out EXPORT defined in asm/asm.h expands to a symbol definition,
so there is no need to define these symbols again. Remove duplicated
symbol definitions.

Fixes: 7aa1c8f4

 ("MIPS: kdump: Add support")
Signed-off-by: Rongwei Zhang <pudh4418@gmail.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>