powerpc: Fix CamelCase checkpatch warnings

85xx, 86xx PowerPC folders have code variables with CamelCase naming conventions.
because of this code checkpatch script generates "WARNING: Avoid CamelCase".

Convert variables name to normal naming convention and modify board, driver
files with updated the new structure.

Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Acked-by: York Sun <yorksun@freescale.com>
diff --git a/board/freescale/p1_twr/ddr.c b/board/freescale/p1_twr/ddr.c
index 697c0dd..67f69d7 100644
--- a/board/freescale/p1_twr/ddr.c
+++ b/board/freescale/p1_twr/ddr.c
@@ -53,7 +53,7 @@
 
 	get_sys_info(&sysinfo);
 	printf("Configuring DDR for %s MT/s data rate\n",
-			strmhz(buf, sysinfo.freqDDRBus));
+			strmhz(buf, sysinfo.freq_ddrbus));
 
 	ddr_size = CONFIG_SYS_SDRAM_SIZE * 1024 * 1024;