feat(s32g274a): enable BL2 early clocks

s32cc_init_early_clks will be used to increase the frequency of the
clocks which have a performance impact on BL2 boot. This set includes
A53, XBAR, DDR and Linflex clocks. For now, it will only contain the
frequency set for FXOSC. More clock management will be added in the next
commits.

Change-Id: Ie85465884de02f5082185f91749f190f40249c2e
Signed-off-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>