lib: os: cbprintf: Use rodata section on sparc

Use rodata region markers to detect if string is read only on
sparc. It was previously disabled but now can be used.

Signed-off-by: Krzysztof Chruscinski <[email protected]>

Author: nordic-krch

lib/os/cbprintf_packaged.c

@@ -31,7 +31,7 @@ static inline bool ptr_in_rodata(const char *addr)
 #define RO_END 0
 #elif defined(CONFIG_ARC) || defined(CONFIG_ARM) || defined(CONFIG_X86) \
 	|| defined(CONFIG_RISCV) || defined(CONFIG_ARM64) \
-	|| defined(CONFIG_NIOS2) || defined(CONFIG_MIPS)
+	|| defined(CONFIG_NIOS2) || defined(CONFIG_MIPS) || defined(CONFIG_SPARC)
 	extern char __rodata_region_start[];
 	extern char __rodata_region_end[];
 #define RO_START __rodata_region_start