gmac_reset

1. call gmac_init_reset

2. Read Gmac Core Reg cmdcfg
3. unset CC_TE, CC_RE, CC_RPI, CC_TAI, CC_HD, CC_ML, CC_CFE, CC_RL, CC_RED, CC_PE, CC_TPI, CC_PAD_EN and CC_PF in cmdcfg if not already unset
4. set CC_PROM, CC_NLC and CC_CFE in cmdcfg if not already set

5. call gmac_clear_reset