feat(nxp-clk): add FXOSC clock enablement

Add the low-level implementation to enable the FXOSC oscillator, which
is disabled by default when booting the SoC. It will be used by PLLs,
for which support will be added later.

Change-Id: Ie784e4e29b8b4453b39d37594c311af940bebf92
Signed-off-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>
4 files changed