[rpmbuild] Use _smp_mflags instead of jobs macro
[rpmbuild] Use _smp_mflags instead of jobs macro

The "jobs" macro is non-standard and won't use multiple cores when
building under mb2.

Signed-off-by: Simo Piiroinen <6d5e5360bed3d486f7d9fb26b0f737f7d4fd45ee@jollamobile.com>

spiiroin/mce,spiiroin/mce,spiiroin/mce,spiiroin/mce