powerpc/powernv: Fix restore of SPRs upon wake up from hypervisor state loss

pnv_wakeup_tb_loss() currently expects cr4 to be "eq" if the CPU is
waking up from a complete hypervisor state loss. Hence, it currently
restores the SPR contents only if cr4 is "eq".

However, after commit bcef83a0 ("powerpc/powernv: Add platform
support for stop instruction"), on ISA v3.0 CPUs, the function
pnv_restore_hyp_resource() sets cr4 to contain the result of the
comparison between the state the CPU has woken up from and the first
deep stop state before calling pnv_wakeup_tb_loss().

Thus if the CPU woke up from a state that is deeper than the first
deep stop state, cr4 will have "gt" set and hence, pnv_wakeup_tb_loss()
will fail to restore the SPRs on waking up from such a state.

Fix the code in pnv_wakeup_tb_loss() to restore the SPR states when cr4
is "eq" or "gt".

Fixes: bcef83a0 ("powerpc/powernv: Add platform support for stop instruction")
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Reviewed-by: Shreyas B. Prabhu <shreyasbp@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>