lame: also disable debug handling on arm(eb)

Not all arm (E.G. non-VFP) toolchains define the control word macros, so
disable debug handling for arm(eb) as well.

As the debug handling has limited value (it simply forces CFLAGS which we
don't want and enables exceptions on FP errors) don't try to be clever about
what toolchain variants to disable it for, but just disable it for all arm(eb).

Fixes http://autobuild.buildroot.net/results/672/672a31c0bd329dec566ba74e0e1be43abd0f16c2/



Signed-off-by: Peter Korsgaard <peter@korsgaard.com>