microblaze: Move individual board linker scripts to common script in cpu tree.

Unification for all microblaze boards.

Signed-off-by: Michal Simek <monstr@monstr.eu>

arch/microblaze/config.mk

@@ -29,3 +29,5 @@ CROSS_COMPILE ?= mb-
 CONFIG_STANDALONE_LOAD_ADDR ?= 0x80F00000
 
 PLATFORM_CPPFLAGS += -ffixed-r31 -D__microblaze__
+
+LDSCRIPT ?= $(SRCTREE)/$(CPUDIR)/u-boot.lds