ppc, crash: enforce KEXEC and KEXEC_FILE to select CRASH_DUMP

In PowerPC, the crash dumping and kexec reboot share code in
arch_kexec_locate_mem_hole(), in which struct crash_mem is used.

Here enfoce enforce KEXEC and KEXEC_FILE to select CRASH_DUMP for now.

[bhe@redhat.com: fix allnoconfig on ppc]
  Link: https://lkml.kernel.org/r/ZbJwMyCpz4HDySoo@MiWiFi-R3L-srv
Link: https://lkml.kernel.org/r/20240124051254.67105-9-bhe@redhat.comSigned-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Pingfan Liu <piliu@redhat.com>
Cc: Klara Modin <klarasmodin@gmail.com>
Cc: Michael Kelley <mhklinux@outlook.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/powerpc/Kconfig

@@ -608,6 +608,11 @@ config PPC64_SUPPORTS_MEMORY_FAILURE
 config ARCH_SUPPORTS_KEXEC
 	def_bool PPC_BOOK3S || PPC_E500 || (44x && !SMP)
 
+config ARCH_SELECTS_KEXEC
+	def_bool y
+	depends on KEXEC
+	select CRASH_DUMP
+
 config ARCH_SUPPORTS_KEXEC_FILE
 	def_bool PPC64
 
@@ -618,6 +623,7 @@ config ARCH_SELECTS_KEXEC_FILE
 	def_bool y
 	depends on KEXEC_FILE
 	select KEXEC_ELF
+	select CRASH_DUMP
 	select HAVE_IMA_KEXEC if IMA
 
 config PPC64_BIG_ENDIAN_ELF_ABI_V2