stm32mp1: rename stpmu1 to stpmic1

This is the correct name of the IP.
Rename stm32mp1_pmic files to stm32mp_pmic.

Change-Id: I238a7d1f9a1d099daf7788dc9ebbd3146ba2f15f
Signed-off-by: Yann Gautier <yann.gautier@st.com>
8 files changed