Support for Artila M-501 starter kit

Kimmo Leppala / Sysart and
Timo Tuunainen / Sysart
diff --git a/board/m501sk/config.mk b/board/m501sk/config.mk
new file mode 100644
index 0000000..9ce161e
--- /dev/null
+++ b/board/m501sk/config.mk
@@ -0,0 +1 @@
+TEXT_BASE = 0x21f00000