Makefile: Make the compiler selectable

Allow people to specify the compiler. For example, if you want to build with gcc-13 you can use: CC=gcc-13 make.

---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index e172758b8b09..651035ab0f77 100644
@@ -5,7 +5,7 @@ VERSION=0.6.4
 OS = linux
 
 
-CC = gcc
+CC ?= gcc
 CXX = g++
 LD = $(CC)
 AR = ar

2.53.0