PPC: Add GS MSR definition

The BookE specification defines MSR bit 28 as Guest State. Add it
to the list of MSR macros.
Signed-off-by: NAlexander Graf <agraf@suse.de>

target-ppc/cpu.h

@@ -420,6 +420,7 @@ struct ppc_slb_t {
 #define MSR_CM   31 /* Computation mode for BookE                     hflags */
 #define MSR_ICM  30 /* Interrupt computation mode for BookE                  */
 #define MSR_THV  29 /* hypervisor state for 32 bits PowerPC           hflags */
+#define MSR_GS   28 /* guest state for BookE                                 */
 #define MSR_UCLE 26 /* User-mode cache lock enable for BookE                 */
 #define MSR_VR   25 /* altivec available                            x hflags */
 #define MSR_SPE  25 /* SPE enable for BookE                         x hflags */
@@ -457,6 +458,7 @@ struct ppc_slb_t {
 #define msr_cm   ((env->msr >> MSR_CM)   & 1)
 #define msr_icm  ((env->msr >> MSR_ICM)  & 1)
 #define msr_thv  ((env->msr >> MSR_THV)  & 1)
+#define msr_gs   ((env->msr >> MSR_GS)   & 1)
 #define msr_ucle ((env->msr >> MSR_UCLE) & 1)
 #define msr_vr   ((env->msr >> MSR_VR)   & 1)
 #define msr_spe  ((env->msr >> MSR_SPE)  & 1)