stm32mp1: zeromem device_info struct ...

The change of the structure highlighted the fact that all fields are not
correctly initialized with zeroes.

Replace the other memset in the function with zeromem, as it is faster.

Change-Id: I27f45a64e34637f79fa519f486bf5936721ef396
Signed-off-by: Yann Gautier <yann.gautier@st.com>

stm32mp1: remove some dependencies on clocks and reset in drivers ...

Include all RCC, clocks and reset headers from stm32mp1_def.h
which if exported to the firmware through platform_def.h.
The same dependency removal is done in common code as well.
Some useless includes are also removed in stm32_sdmmc2 driver.

Change-Id: I731ea5775c3fdb7f7b0c388b93923ed5e84b8d3f
Signed-off-by: Yann Gautier <yann.gautier@st.com>

stm32mp1: make functions and macros more common ...

Mainly remove suffix 1 from prefix stm32mp1 in several macros and functions
that can be used in drivers shared by different platforms.

Change-Id: I2295c44f5b1edac7e80a93c0e8dfd671b36e88e7
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>

stm32mp1: split code between common and private parts ...

Some parts of code could be shared with platform derivatives,
or new platforms.
A new folder plat/st/common is created to put common parts.

stm32mp_common.h is a common API aggregate.

Remove some casts where applicable.
Fix some types where applicable.
Remove also some platform includes that are already in stm32mp1_def.h.

Change-Id: I46d763c8d9e15732d1ee7383207fd58206d7f583
Signed-off-by: Yann Gautier <yann.gautier@st.com>
Signed-off-by: Etienne Carriere <etienne.carriere@st.com>