OMAP2+: hwmod: Do not write the enawakeup bit if SYSC_HAS_ENAWAKEUP is not set

The Type 2 type of IPs will not have any enawakeup bit in their sysconfig.
Writing to that bit will instead trigger a softreset.
Check the flag to write this bit only if the module supports it.

Reported-by: Miguel Vadillo <vadillo@ti.com>
Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>