ARC: Don't use "+l" inline asm constraint

commit 3c7c7a2f upstream.

Apparenty this is coming in the way of gcc fix which inhibits the usage
of LP_COUNT as a gpr.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>