flashbench: force gnu99 dialect on sh2a

Fixes:
http://autobuild.buildroot.org/results/33880036054c39cb04dad71bc8c0a9eece16fac6

CodeSourcery toolchains for sh2a only provide LLONG_MAX when
used with the gnu99 dialect.

Signed-off-by: Gilles Talis <gilles.talis@gmail.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
quota: needs mmu

Fixes http://autobuild.buildroot.net/results/85e3c73d1c0b5c6843d65a487203b20f62bf3075

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>