tests: logging: Update test after adding rodata detection on sparc

Updated tests to tread sparc as any other platforms that are
capable of detection if string is read only.

Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
diff --git a/tests/subsys/logging/log_api/src/test.inc b/tests/subsys/logging/log_api/src/test.inc
index 47cf47c..1b5160f 100644
--- a/tests/subsys/logging/log_api/src/test.inc
+++ b/tests/subsys/logging/log_api/src/test.inc
@@ -321,7 +321,7 @@
 			    HEXDUMP_BYTES_CONT_MSG * (msgs_in_buf - 1);
 }
 
-#if defined(__sparc__) || defined(CONFIG_ARCH_POSIX)
+#if defined(CONFIG_ARCH_POSIX)
 #define STR_SIZE(s) (strlen(s) + 2 * sizeof(char))
 #else
 #define STR_SIZE(s) 0
diff --git a/tests/subsys/logging/log_msg2/src/main.c b/tests/subsys/logging/log_msg2/src/main.c
index 575b783..272a4b1 100644
--- a/tests/subsys/logging/log_msg2/src/main.c
+++ b/tests/subsys/logging/log_msg2/src/main.c
@@ -19,7 +19,7 @@
 #include <ztest.h>
 #include <sys/cbprintf.h>
 
-#if defined(__sparc__) || defined(CONFIG_ARCH_POSIX)
+#if defined(CONFIG_ARCH_POSIX)
 /* On some platforms all strings are considered RW, that impacts size of the
  * package.
  */