checkasm/sw_rgb: Revert test additions from e18b46d95f

The unaligned width test cases fail on i386; we have an assembly
function of rgb24toyv12 which is enabled only within
"#if ARCH_X86_32 && HAVE_7REGS", which seems to fail these new
test cases for unaligned widths.

As that assembly function has existed for a long time in that form,
the issue probably isn't very recent, thus skip testing these cases
for now.

Once the assembly function has been fixed, these test cases can
be readded.

Signed-off-by: Martin Storsjö <martin@martin.st>
(cherry picked from commit 157ce21939)
Signed-off-by: Martin Storsjö <martin@martin.st>

tests/checkasm/sw_rgb.c

@@ -129,7 +129,7 @@ static int cmp_off_by_n(const uint8_t *ref, const uint8_t *test, size_t n, int a
 
 static void check_rgb24toyv12(struct SwsContext *ctx)
 {
-    static const int input_sizes[] = {2, 16, 128, 540, MAX_LINE_SIZE, -MAX_LINE_SIZE};
+    static const int input_sizes[] = {16, 128, 512, MAX_LINE_SIZE, -MAX_LINE_SIZE};
 
     LOCAL_ALIGNED_32(uint8_t, src, [BUFSIZE * 3]);
     LOCAL_ALIGNED_32(uint8_t, buf_y_0, [BUFSIZE]);