raw/ifpga/base: enhance driver reliability in multi-process

raw/ifpga/base: enhance driver reliability in multi-process

Current hardware protection is based on pthread mutex which
work just for situation of multi-thread in one process. In
multi-process environment, hardware state machine would be
corrupted by concurrent access, that means original pthread
mutex mechanism need be enhanced.

The major modifications in this patch are list below:
1. Create a mutex for adapter in shared memory named
   "mutex.IFPGA:domain:bus:dev.func" when device is probed.
2. Create a shared memory named "IFPGA:domain:bus:dev.func" during opae
   adapter is initializing. There is a reference count in shared memory.
   Shared memory will be destroyed once reference count turned to zero.
3. Two mutexs are created in shared memory and initialized with flag
   PTHREAD_PROCESS_SHARED. One for SPI and the other for I2C. They will
   be passed to SPI and I2C driver subsequently.
4. DTB data in flash will be cached in shared memory. Then MAX10 driver
   can read DTB from shared memory instead of flash. This avoid
   confliction of concurrent flash access between hardware and software.

Signed-off-by: Wei Huang <wei.huang@intel.com>
Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com>
Acked-by: Rosen Xu <rosen.xu@intel.com>