Bump dependency to SDCC 4.4

SDCC 4.2 doesn't build anymore on arm macOS Sonora. Bump dependency
to a version that supports this OS combination.

Ref dciabrin/homebrew-ngdevkit#6

Makefile

@@ -46,7 +46,7 @@ SRC_BINUTILS=binutils-2.35.2
 SRC_GCC=gcc-11.4.0
 SRC_NEWLIB=newlib-4.0.0
 SRC_GDB=gdb-9.2
-SRC_SDCC=sdcc-src-4.2.0
+SRC_SDCC=sdcc-src-4.4.0
 
 TOOLCHAIN=ngbinutils nggcc ngnewlib ngsdcc nggdb