board: st: stpmic1: add function stpmic1_init

Add a function stmpic_init to early initialize the PMIC STPMIC1
- keep vdd on during the reset cycle (to avoid issue when backup battery
  is absent)
- Check if debug is enabled to program PMIC according to the bit

This patch allows to remove the compilation of spl.c file from stm32mp1
board in dh_stm32mp1.

CONFIG_SPL_BOARD_INIT is removed as the new function is called earlier
in SPL, in the function board_early_init_f.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/configs/stm32mp15_basic_defconfig b/configs/stm32mp15_basic_defconfig
index ecdbac6..28363e9 100644
--- a/configs/stm32mp15_basic_defconfig
+++ b/configs/stm32mp15_basic_defconfig
@@ -18,6 +18,7 @@
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_FIT=y
 CONFIG_BOOTCOMMAND="run bootcmd_stm32mp"
+CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION=y
 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION=3
 CONFIG_SPL_I2C_SUPPORT=y