Blackfin: dpmc: omit RETE/RETN when hibernating

The RETE/RETN registers are only used in emulation(JTAG) and NMI nodes,
or as scratch registers, neither of which need to be saved/restored as
this code doesn't execute at those core event levels.

Signed-off-by: Mike Frysinger <[e-mail]>

arch/blackfin/mach-common/dpmc_modes.S

···
 	r0 = RETI;
 	[--sp] = r0;
 	[--sp] = RETX;
-	[--sp] = RETN;
-	[--sp] = RETE;
 	[--sp] = SEQSTAT;
 
 	/* Save Magic, return address and Stack Pointer */
···
 
 	/* Restore Core Registers */
 	SEQSTAT = [sp++];
-	RETE = [sp++];
-	RETN = [sp++];
 	RETX = [sp++];
 	r0 = [sp++];
 	RETI = r0;