Use a common u-boot.lds file across all AT91CAP9/AT91SAM9 platforms

All the AT91CAP9/AT91SAM9 boards have the same linker script. The patch
below avoids the duplication of u-boot.lds by putting the file in the
cpu directory instead of the board one.

Signed-off-by: Stelian Pop <stelian@popies.net>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/cpu/arm926ejs/at91sam9/config.mk b/cpu/arm926ejs/at91sam9/config.mk
index ca2cae1..83040eb 100644
--- a/cpu/arm926ejs/at91sam9/config.mk
+++ b/cpu/arm926ejs/at91sam9/config.mk
@@ -1,2 +1,3 @@
 PLATFORM_CPPFLAGS += -march=armv5te
 PLATFORM_CPPFLAGS += $(call cc-option,-mtune=arm926ejs,)
+LDSCRIPT := $(SRCTREE)/cpu/arm926ejs/at91sam9/u-boot.lds