powerpc: Enable passing IMA log to next kernel on kexec

CONFIG_HAVE_IMA_KEXEC is enabled to indicate that the IMA measurement
log information is present in the device tree. This should be selected
only if CONFIG_IMA is enabled.

Update CONFIG_KEXEC_FILE to select CONFIG_HAVE_IMA_KEXEC, if CONFIG_IMA
is enabled, to indicate that the IMA measurement log information is
present in the device tree for powerpc.

Signed-off-by: Lakshmi Ramasubramanian <[e-mail]>
Suggested-by: Thiago Jung Bauermann <[e-mail]>
Reviewed-by: Thiago Jung Bauermann <[e-mail]>
Signed-off-by: Rob Herring <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/powerpc/Kconfig

···
 config KEXEC_FILE
 	bool "kexec file based system call"
 	select KEXEC_CORE
-	select HAVE_IMA_KEXEC
+	select HAVE_IMA_KEXEC if IMA
 	select BUILD_BIN2C
 	select KEXEC_ELF
 	depends on PPC64