sys: random: make use of submodules in Makefile

Makefile.dep

@@ -596,6 +596,7 @@ ifneq (,$(filter conn_can,$(USEMODULE)))
 endif
 
 ifneq (,$(filter random,$(USEMODULE)))
+  USEMODULE += prng
   # select default prng
   ifeq (,$(filter prng_%,$(USEMODULE)))
     USEMODULE += prng_tinymt32

makefiles/pseudomodules.inc.mk

@@ -53,6 +53,8 @@ PSEUDOMODULES += openthread
 PSEUDOMODULES += pktqueue
 PSEUDOMODULES += posix
 PSEUDOMODULES += printf_float
+PSEUDOMODULES += prng
+PSEUDOMODULES += prng_%
 PSEUDOMODULES += saul_adc
 PSEUDOMODULES += saul_default
 PSEUDOMODULES += saul_gpio

sys/auto_init/auto_init.c

@@ -80,7 +80,7 @@
 #include "net/fib.h"
 #endif
 
-#ifdef MODULE_TINYMT32
+#ifdef MODULE_PRNG
 #include "random.h"
 #endif
 
@@ -93,7 +93,7 @@
 
 void auto_init(void)
 {
-#ifdef MODULE_TINYMT32
+#ifdef MODULE_PRNG
     random_init(0);
 #endif
 #ifdef MODULE_XTIMER

sys/random/Makefile

-ifneq (,$(filter prng_mersenne,$(USEMODULE)))
-    SRC += mersenne.c
-endif
-ifneq (,$(filter prng_minstd,$(USEMODULE)))
-    SRC += minstd.c
-endif
-ifneq (,$(filter prng_musl_lcg,$(USEMODULE)))
-    SRC += musl_lcg.c
-endif
+BASE_MODULE := prng
+SUBMODULES := 1
+
 ifneq (,$(filter prng_tinymt32,$(USEMODULE)))
-    SRC += prng_tinymt32.c
     DIRS += tinymt32
 endif