package/dvb-apps: requires kernel headers >= 3.3

dvb-apps requires linux kernel headers >= 3.3, for:
    SYS_TURBO, SYS_DVBC_ANNEX_A      : introduced in 3.2
    SYS_DVBC_ANNEX_C, DTV_ENUM_DELSYS: introduced in 3.3

Fixes:
    http://autobuild.buildroot.net/results/a77/a7786dffa28e5472fbc9c8fe4ab302c84d7a3cb9



Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>