Revert "PowerPC: Add support for -msingle-pic-base"

This reverts commit 39768f7715ed637ef02f49fc7de664cc1aaf14b3.

Reson: it breaks a number of boards with embedded environment as the
code size grows in some places.
diff --git a/arch/powerpc/cpu/mpc5xx/start.S b/arch/powerpc/cpu/mpc5xx/start.S
index 4fb2047..cc11c8f 100644
--- a/arch/powerpc/cpu/mpc5xx/start.S
+++ b/arch/powerpc/cpu/mpc5xx/start.S
@@ -174,11 +174,7 @@
 	/*----------------------------------------------------------------------*/
 
 	GET_GOT			/* initialize GOT access			*/
-#if defined(__pic__) && __pic__ == 1
-	/* Needed for upcoming -msingle-pic-base */
-	bl	_GLOBAL_OFFSET_TABLE_@local-4
-	mflr	r30
-#endif
+
 	/* r3: IMMR */
 	bl	cpu_init_f	/* run low-level CPU init code     (from Flash)	*/
 
@@ -367,11 +363,6 @@
 	mr	r10, r5		/* Save copy of monitor destination Address in SRAM */
 
 	GET_GOT
-#if defined(__pic__) && __pic__ == 1
-	/* Needed for upcoming -msingle-pic-base */
-	bl	_GLOBAL_OFFSET_TABLE_@local-4
-	mflr	r30
-#endif
 	mr	r3,  r5				/* Destination Address	*/
 	lis	r4, CONFIG_SYS_MONITOR_BASE@h		/* Source      Address	*/
 	ori	r4, r4, CONFIG_SYS_MONITOR_BASE@l