arm: testsuite: improve compatibility of gcc.target/arm/pr19599.c

Add +fp to the architecture specification, so that -mfpu=auto works
with the hard-float ABI.

gcc/testsuite:

	* gcc.target/arm/pr19599.c: Add +fp to the architecture.

gcc/testsuite/gcc.target/arm/pr19599.c

@@ -1,6 +1,6 @@
 /* { dg-skip-if "need at least armv5te" { *-*-* } { "-march=armv[234]*" "-mthumb" } { "" } } */
 /* { dg-skip-if "FDPIC does not support armv5te" { arm*-*-uclinuxfdpiceabi } "*" "" } */
-/* { dg-options "-O2 -march=armv5te -marm" }  */
+/* { dg-options "-O2 -march=armv5te+fp -marm" }  */
 /* { dg-final { scan-assembler "bx" } } */
 
 int (*indirect_func)();