When ipa_check_hw_present() returns false, g_ipa_config
is left as NULL pointer. ipa_config_is_enabled() and
ipa_config_is_uc_enabled() will lead to NULL pointer
dereference.
Fix is to check against g_ipa_config NULL pointer
in ipa_config_is_enabled() and ipa_config_is_uc_enabled().
Change-Id: I95da7aede7d72db8591102eea7504cad59686105
CRs-Fixed: 2246224