[ARM] Cortex-R5 is not VFPOnlySP

This patch fixes the error in ARM.td which stated that Cortex-R5
floating point unit can do only single precision, when it can do double as well.

Reviewers: rengolin

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D10769

llvm-svn: 240799