powerpc/mpc85xx: fix TLB alignment

In the RAMBOOT/SPL case we were creating a TLB entry starting at
CONFIG_SYS_MONITOR_BASE, and just hoping that the base was properly
aligned for the TLB entry size.  This turned out to not be the case
with NAND SPL because the main U-Boot starts at an offset into the image
in order to skip the SPL itself.

Fix the TLB entry to always start at a proper alignment.  We still assume that
CONFIG_SYS_MONITOR_BASE doesn't start immediately before a large-page boundary
thus requiring multiple TLB entries.
Signed-off-by: NScott Wood <scottwood@frescale.com>
Cc: Andy Fleming <afleming@freescale.com>

arch/powerpc/cpu/mpc85xx/start.S

@@ -1046,8 +1046,8 @@ create_init_ram_area:
 	*/
 	create_tlb1_entry 15, \
 		1, BOOKE_PAGESZ_1M, \
-		CONFIG_SYS_MONITOR_BASE, MAS2_I|MAS2_G, \
-		CONFIG_SYS_PBI_FLASH_WINDOW, MAS3_SX|MAS3_SW|MAS3_SR, \
+		CONFIG_SYS_MONITOR_BASE & 0xfff00000, MAS2_I|MAS2_G, \
+		CONFIG_SYS_PBI_FLASH_WINDOW & 0xfff00000, MAS3_SX|MAS3_SW|MAS3_SR, \
 		0, r6
 #else
 	/*
@@ -1056,8 +1056,8 @@ create_init_ram_area:
 	 */
 	create_tlb1_entry 15, \
 		1, BOOKE_PAGESZ_1M, \
-		CONFIG_SYS_MONITOR_BASE, MAS2_I|MAS2_G, \
-		CONFIG_SYS_MONITOR_BASE, MAS3_SX|MAS3_SW|MAS3_SR, \
+		CONFIG_SYS_MONITOR_BASE & 0xfff00000, MAS2_I|MAS2_G, \
+		CONFIG_SYS_MONITOR_BASE & 0xfff00000, MAS3_SX|MAS3_SW|MAS3_SR, \
 		0, r6
 #endif