powerpc/xmon: Add some more elements to the existing PACA dump list

This patch adds a set of new elements to the existing PACA dump list
inside an xmon session which can be listed below improving the overall
xmon debug support.

With this patch, a typical xmon PACA dump looks something like this.

paca for cpu 0x0 @ c00000000fdc0000:
 possible             = yes
 present              = yes
 online               = yes
 lock_token           = 0x8000            	(0xa)
 paca_index           = 0x0               	(0x8)
 kernel_toc           = 0xc000000001393200	(0x10)
 kernelbase           = 0xc000000000000000	(0x18)
 kernel_msr           = 0xb000000000001033	(0x20)
 emergency_sp         = 0xc00000003fff0000	(0x28)
 mc_emergency_sp      = 0xc00000003ffec000	(0x2e0)
 in_mce               = 0x0               	(0x2e8)
 hmi_event_available  = 0x0               	(0x2ea)
 data_offset          = 0x1fe7b0000       	(0x30)
 hw_cpu_id            = 0x0               	(0x38)
 cpu_start            = 0x1               	(0x3a)...