km/powerpc: migrate to env.txt file

Use already present common.env file and add a powerpc specific env
so that we can move all the environment defines to text files.

Signed-off-by: Holger Brunck <holger.brunck@hitachienergy.com>
diff --git a/include/environment/pg-wcom/powerpc.env b/include/environment/pg-wcom/powerpc.env
new file mode 100644
index 0000000..a57fd93
--- /dev/null
+++ b/include/environment/pg-wcom/powerpc.env
@@ -0,0 +1,14 @@
+arch=ppc_82xx
+bootm_mapsize=CONFIG_SYS_BOOTM_LEN
+checkfdt=true
+set_fdthigh=true
+
+update=protect off BOOTFLASH_START +${filesize} &&
+       erase BOOTFLASH_START +${filesize} &&
+       cp.b ${load_addr_r} BOOTFLASH_START ${filesize} &&
+       protect on BOOTFLASH_START +${filesize}
+
+newenv=prot off CONFIG_ENV_ADDR +0x40000 &&
+       era CONFIG_ENV_ADDR +0x40000
+
+unlock=yes