st: pmic: initialize i2c_state

Make sure that i2c->i2c_state is correctly initialized
with I2C_STATE_RESET value this avoid hi2c->lock to not
be set to 0 when calling stm32_i2c_init during platform
suspend/resume operations.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Change-Id: I3b4c1f9115589325eb256789a1764c322741db7d
Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/tf-a/+/161037


Reviewed-by: CITOOLS <smet-aci-reviews@lists.codex.cro.st.com>
Reviewed-by: CIBUILD <smet-aci-builds@lists.codex.cro.st.com>
Reviewed-by: Nicolas LE BAYON <nicolas.le.bayon@st.com>
Reviewed-by: Yann GAUTIER <yann.gautier@st.com>