fix: avoid macro redefinition by namespacing helpers

Rename is_aligned and align_up to libtl_* variants and move header to
private include path. Prevents clashes with external projects that
define similar macros (e.g., TF-A).

Change-Id: I7e13efa55fe120dccc68d2a941dea7cdd1f005a6
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 71b5b35..b69df14 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -21,7 +21,11 @@
 SET(TARGET_GROUP release CACHE STRING "Specify the Build Target [\"release\" by default]")
 
 add_library(tl STATIC "${CMAKE_CURRENT_SOURCE_DIR}/src/transfer_list.c")
-target_include_directories(tl PUBLIC include)
+target_include_directories(tl
+    PUBLIC
+        ${PROJECT_SOURCE_DIR}/include
+)
+
 target_link_libraries(tl PUBLIC cxx_compiler_flags)
 
 if(TARGET_GROUP STREQUAL test)