LoongArch: Calculate various sizes in the linker script

mainline inclusion
from mainline-v6.5-rc1
commit 414cefc7
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7MWTU


CVE: NA

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Taking the address delta between symbols in different sections is not
supported by the LLVM IAS. Instead, do this in the linker script, so
the same data can be properly referenced in assembly.

Signed-off-by: Yongzhen Zhang <zhangyongzhen@kylinos.cn>
Signed-off-by: WANG Rui <wangrui@loongson.cn>
Signed-off-by: WANG Xuerui <git@xen0n.name>
[chenhuacai: Fix build with !CONFIG_EFI_STUB]
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>