sh: make the linker scripts more generic

currently we need to sync the linker script enty and TEXT_BASE manualy
and the reloc_dst is based on it

instead provide it now from the ldflags

tested on r2dplus

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/sh_config.mk b/sh_config.mk
index 49d50f7..c19db53 100644
--- a/sh_config.mk
+++ b/sh_config.mk
@@ -22,3 +22,4 @@
 #
 
 PLATFORM_CPPFLAGS += -DCONFIG_SH -D__SH__
+PLATFORM_LDFLAGS += -e $(TEXT_BASE) --defsym reloc_dst=$(TEXT_BASE)