KVM: PPC: add missing MODULE_DESCRIPTION() macros

With ARCH=powerpc, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in arch/powerpc/kvm/test-guest-state-buffer.o
WARNING: modpost: missing MODULE_DESCRIPTION() in arch/powerpc/kvm/kvm-pr.o
WARNING: modpost: missing MODULE_DESCRIPTION() in arch/powerpc/kvm/kvm-hv.o

Add the missing invocations of the MODULE_DESCRIPTION() macro.
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
[mpe: Change kvm-hv description to mention POWER8 & later]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240615-md-powerpc-arch-powerpc-kvm-v1-1-7478648b3100@quicinc.com

arch/powerpc/kvm/book3s_hv.c

@@ -6617,6 +6617,7 @@ static void kvmppc_book3s_exit_hv(void)
 
 module_init(kvmppc_book3s_init_hv);
 module_exit(kvmppc_book3s_exit_hv);
+MODULE_DESCRIPTION("KVM on Book3S (POWER8 and later) in hypervisor mode");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_MISCDEV(KVM_MINOR);
 MODULE_ALIAS("devname:kvm");

arch/powerpc/kvm/book3s_pr.c

@@ -2111,6 +2111,7 @@ void kvmppc_book3s_exit_pr(void)
 module_init(kvmppc_book3s_init_pr);
 module_exit(kvmppc_book3s_exit_pr);
 
+MODULE_DESCRIPTION("KVM on Book3S without using hypervisor mode");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_MISCDEV(KVM_MINOR);
 MODULE_ALIAS("devname:kvm");

arch/powerpc/kvm/test-guest-state-buffer.c

@@ -325,4 +325,5 @@ static struct kunit_suite guest_state_buffer_test_suite = {
 
 kunit_test_suites(&guest_state_buffer_test_suite);
 
+MODULE_DESCRIPTION("KUnit tests for Guest State Buffer APIs");
 MODULE_LICENSE("GPL");