selftests/bpf: Add alignment flag for test_verifier 190 testcase

There exists failure when executing the testcase "./test_verifier 190" if
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is not set on LoongArch.

  #190/p calls: two calls that return map_value with incorrect bool check FAIL
  ...
  misaligned access off (0x0; 0xffffffffffffffff)+0 size 8
  ...
  Summary: 0 PASSED, 0 SKIPPED, 1 FAILED

It means that the program has unaligned accesses, but the kernel sets
CONFIG_ARCH_STRICT_ALIGN by default to enable -mstrict-align to prevent
unaligned accesses, so add a flag F_NEEDS_EFFICIENT_UNALIGNED_ACCESS
into the testcase to avoid the failure.

This is somehow similar with the commit ce1f289 ("selftests/bpf:
Add F_NEEDS_EFFICIENT_UNALIGNED_ACCESS to some tests").

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>

Author: seehearfeel

tools/testing/selftests/bpf/verifier/calls.c

@@ -1521,6 +1521,7 @@
 	.errstr = "R0 invalid mem access 'scalar'",
 	.result_unpriv = REJECT,
 	.errstr_unpriv = "invalid read from stack R7 off=-16 size=8",
+	.flags = F_NEEDS_EFFICIENT_UNALIGNED_ACCESS,
 },
 {
 	"calls: two calls that receive map_value via arg=ptr_stack_of_caller. test1",