[PATCH] riscv: Fixup compile error with !MMU

[guoren]

From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>

Current nommu_virt_defconfig can't compile:

In file included from
arch/riscv/kernel/crash_core.c:3:
arch/riscv/kernel/crash_core.c:
In function 'arch_crash_save_vmcoreinfo':
arch/riscv/kernel/crash_core.c:8:27:
error: 'VA_BITS' undeclared (first use in this function)
    8 |         VMCOREINFO_NUMBER(VA_BITS);
      |                           ^~~~~~~

Add MMU dependency for KEXEC_FILE.

Fixes: 6261586e0c91 ("RISC-V: Add kexec_file support")
Reported-by: Conor Dooley <conor@xxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Guo Ren <guoren@xxxxxxxxxx>
Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
---
 arch/riscv/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index ef8d66de5f38..91319044fd13 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -496,7 +496,7 @@ config KEXEC_FILE
 	select KEXEC_CORE
 	select KEXEC_ELF
 	select HAVE_IMA_KEXEC if IMA
-	depends on 64BIT
+	depends on 64BIT && MMU
 	help
 	  This is new version of kexec system call. This system call is
 	  file based and takes file descriptors as system call argument
-- 
2.36.1