riscv: kdump: fix crashkernel reserving problem on RISC-V

riscv: kdump: fix crashkernel reserving problem on RISC-V

When testing on risc-v QEMU environment with "crashkernel="
parameter enabled, a problem occurred with the following
message:

[    0.000000] crashkernel low memory reserved: 0xf8000000 - 0x100000000 (128 MB)
[    0.000000] crashkernel reserved: 0x0000000177e00000 - 0x0000000277e00000 (4096 MB)
[    0.000000] ------------[ cut here ]------------
[    0.000000] WARNING: CPU: 0 PID: 0 at kernel/resource.c:779 __insert_resource+0x8e/0xd0
[    0.000000] Modules linked in:
[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.6.0-rc2-next-20230920 #1
[    0.000000] Hardware name: riscv-virtio,qemu (DT)
[    0.000000] epc : __insert_resource+0x8e/0xd0
[    0.000000]  ra : insert_resource+0x28/0x4e
[    0.000000] epc : ffffffff80017344 ra : ffffffff8001742e sp : ffffffff81203db0
[    0.000000]  gp : ffffffff812ece98 tp : ffffffff8120dac0 t0 : ff600001f7ff2b00
[    0.000000]  t1 : 0000000000000000 t2 : 3428203030303030 s0 : ffffffff81203dc0
[    0.000000]  s1 : ffffffff81211e18 a0 : ffffffff81211e18 a1 : ffffffff81289380
[    0.000000]  a2 : 0000000277dfffff a3 : 0000000177e00000 a4 : 0000000177e00000
[    0.000000]  a5 : ffffffff81289380 a6 : 0000000277dfffff a7 : 0000000000000078
[    0.000000]  s2 : ffffffff81289380 s3 : ffffffff80a0bac8 s4 : ff600001f7ff2880
[    0.000000]  s5 : 0000000000000280 s6 : 8000000a00006800 s7 : 000000000000007f
[    0.000000]  s8 : 0000000080017038 s9 : 0000000080038ea0 s10: 0000000000000000
[    0.000000]  s11: 0000000000000000 t3 : ffffffff80a0bc00 t4 : ffffffff80a0bc00
[    0.000000]  t5 : ffffffff80a0bbd0 t6 : ffffffff80a0bc00
[    0.000000] status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003
[    0.000000] [<ffffffff80017344>] __insert_resource+0x8e/0xd0
[    0.000000] ---[ end trace 0000000000000000 ]---
[    0.000000] Failed to add a Crash kernel resource at 177e00000

The crashkernel memory has been allocated successfully, whereas
it failed to insert into iomem_resource. This is due to the
unique reserving logic in risc-v arch specific code, i.e.
crashk_res/crashk_low_res will be added into iomem_resource
later in init_resources(), which is not aligned with current
unified reserving logic in reserve_crashkernel_{generic,low}()
and therefore leads to the failure of crashkernel reservation.

Removing the arch specific code within #ifdef CONFIG_KEXEC_CORE
in init_resources() to fix above problem.

Fixes: 31549153088e ("riscv: kdump: use generic interface to simplify crashkernel reservation")
Signed-off-by: Chen Jiahao <chenjiahao16@huawei.com>
Link: https://lore.kernel.org/r/20230925024333.730964-1-chenjiahao16@huawei.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>