Introduce 'spec' subdirectories to outline aspects

Instead of holding SPEC-variable dependent files and directories inline
within the repository structure, move them into 'spec' subdirectories
at the corresponding levels, e.g.:

  repos/base/include/spec
  repos/base/mk/spec
  repos/base/lib/mk/spec
  repos/base/src/core/spec
  ...

Moreover, this commit removes the 'platform' directories. That term was
used in an overloaded sense. All SPEC-relative 'platform' directories are
now named 'spec'. Other files, like for instance those related to the
kernel/architecture specific startup library, where moved from 'platform'
directories to explicit, more meaningful places like e.g.: 'src/lib/startup'.

Fix #1673

repos/dde_rump/include/spec/arm/rump_cgd/device.h

@@ -10,12 +10,13 @@
  * This file is part of the Genode OS framework, which is distributed
  * under the terms of the GNU General Public License version 2.
  */
-#ifndef _INCLUDE__ARM_RUMP_CGD__DEVICE_H_
-#define _INCLUDE__ARM_RUMP_CGD__DEVICE_H_
+
+#ifndef _INCLUDE__SPEC__ARM__RUMP_CGD__DEVICE_H_
+#define _INCLUDE__SPEC__ARM__RUMP_CGD__DEVICE_H_
 
 /**
  * Cgd raw device used within rump
  */
 #define CGD_RAW_DEVICE       "/dev/rcgd0c"
 
-#endif /* _INCLUDE__ARM_RUMP_CGD__DEVICE_H_ */
+#endif /* _INCLUDE__SPEC__ARM__RUMP_CGD__DEVICE_H_ */

repos/dde_rump/include/spec/x86/rump_cgd/device.h

@@ -10,12 +10,13 @@
  * This file is part of the Genode OS framework, which is distributed
  * under the terms of the GNU General Public License version 2.
  */
-#ifndef _INCLUDE__X86_RUMP_CGD__DEVICE_H_
-#define _INCLUDE__X86_RUMP_CGD__DEVICE_H_
+
+#ifndef _INCLUDE__SPEC__X86__RUMP_CGD__DEVICE_H_
+#define _INCLUDE__SPEC__X86__RUMP_CGD__DEVICE_H_
 
 /**
  * Cgd raw device used within rump
  */
 #define CGD_RAW_DEVICE       "/dev/rcgd0d"
 
-#endif /* _INCLUDE__X86_RUMP_CGD__DEVICE_H_ */
+#endif /* _INCLUDE__SPEC__X86__RUMP_CGD__DEVICE_H_ */

repos/dde_rump/lib/mk/rump.inc

@@ -17,7 +17,7 @@ SHARED_LIB  = yes
 LD_OPT      += --whole-archive --start-group $(ARCHIVE) --end-group \
                --no-whole-archiv
 
-LD_SCRIPT_SO = $(call select_from_repositories,src/platform/genode_rel.ld) \
-               -T$(REP_DIR)/src/platform/rump.ld
+LD_SCRIPT_SO = $(call select_from_repositories,src/ld/genode_rel.ld) \
+               -T$(REP_DIR)/src/ld/rump.ld
 
 # vi:set ft=make :