rtems_config: Change config options based on BSP name

This replaces an implementation that used a header guard being defined
to indicate BSP specific options.  Hopefully this method is more
explicit when config options should be set for specific BSPs.

modules/libcom/RTEMS/Makefile

@@ -37,6 +37,8 @@ ifeq ($(RTEMS_TARGET_CPU),i386)
 rtemsCom_SRCS += ne2kpci.c
 endif
 
+rtems_config_CPPFLAGS += -DBSP_$(RTEMS_BSP)
+
 LIBRARY_RTEMS = rtemsCom
 
 # shared library ABI version.

modules/libcom/RTEMS/posix/rtems_config.c

@@ -153,9 +153,9 @@ extern void *POSIX_Init(void *argument);
 #define CONFIGURE_APPLICATION_NEEDS_RTC_DRIVER
 #endif
 
-#if defined(LIBBSP_I386_PC386_BSP_H)
+#if defined(BSP_pc386) || defined(BSP_pc686)
 #define RTEMS_BSD_CONFIG_DOMAIN_PAGE_MBUFS_SIZE (64 * 1024 * 1024)
-#elif defined(LIBBSP_POWERPC_QORIQ_BSP_H)
+#elif defined(BSP_qoriq_e500)
 #define RTEMS_BSD_CONFIG_DOMAIN_PAGE_MBUFS_SIZE (32 * 1024 * 1024)
 #endif