Drivers shall be re-entrant

[nashif]

Reported by Kuo-Lang Tseng:

Drivers implementation shall be re-entrant; it should be safe to concurrently call 2 or more instances of the same driver with pre-emptible multitasking.

• [x] GH-404: Add driver API reentrancy support to UART shim drivers
• [x] GH-392: Add driver API reentrancy support to GPIO shim drivers
• [x] GH-391: Add driver API reentrancy support to WDT shim driver
• [x] GH-390: Add driver API reentrancy support to ADC shim driver
• [x] GH-383: Add driver API reentrancy support to PWM shim driver
• [x] GH-379: AON counter driver needs to add driver API reentrancy support
• [x] GH-369: Add driver API reentrancy support to flash driver
• [x] GH-367: Add driver API reentrancy support to RTC driver for LMT
• [x] GH-366: Add driver API reentrancy support to I2C driver for ARC
• [x] GH-365: Add driver API reentrancy support to SPI driver for ARC
• [x] GH-364: Add driver API reentrancy support to I2C driver for LMT
• [x] GH-363: Add driver API reentrancy support to SPI driver for LMT

(Imported from Jira ZEP-406)

[nashif]

by Lei Liu:

Case: test_spi_master_2_instance_write Pass on LMT & ARC. Verified GH-363 & GH-365.