refactor(libc): clean up dependencies in libc

- Removing platform dependencies from libc modules.
- Replacing panicking with actual error handling.
- Debug macros are included indirectly from assert.h. Removing
  "platform_def.h" from assert.h and adding "common/debug.h"
  where the macros are used.
- Removing hack for fixing PLAT_LOG_LEVEL_ASSERT to 40.
  Instead removing assert with expression, as this
  does not provide additional information.

Signed-off-by: Claus Pedersen <claustbp@google.com>
Change-Id: Icc201ea7b63c1277e423c1cfd13fd6816c2bc568
diff --git a/plat/imx/imx8m/imx8m_dyn_cfg_helpers.c b/plat/imx/imx8m/imx8m_dyn_cfg_helpers.c
index 8b2fdd6..5d65ef2 100644
--- a/plat/imx/imx8m/imx8m_dyn_cfg_helpers.c
+++ b/plat/imx/imx8m/imx8m_dyn_cfg_helpers.c
@@ -13,6 +13,7 @@
 #endif
 #include <common/fdt_wrappers.h>
 #include <libfdt.h>
+#include <platform_def.h>
 
 #define DTB_PROP_HW_LOG_ADDR	"tpm_event_log_addr"
 #define DTB_PROP_HW_LOG_SIZE	"tpm_event_log_size"