x86/ima: fix the Kconfig dependency for IMA_ARCH_POLICY

If enabled, ima arch specific policies always adds the measurements rules,
this makes it dependent on CONFIG_IMA. CONFIG_IMA_APPRAISE implicitly takes
care of this, however it is needed explicitly for CONFIG_KEXEC_VERIFY_SIG.

This patch adds the CONFIG_IMA dependency in combination with
CONFIG_KEXEC_VERIFY_SIG for CONFIG_IMA_ARCH_POLICY

Fixes: d958083a

 (x86/ima: define arch_get_ima_policy() for x86)
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Dave Young <dyoung@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>