mimxrt10xx: Utilize the Keypad peripheral in RT1062

[arturo182]

From datasheet:

The KPP is a 16-bit peripheral that can be used as a keypad matrix interface or as general purpose
input/output (I/O). It supports 8 x 8 external key pad matrix. Main features are:
• Multiple-key detection
• Long key-press detection
• Standby key-press detection
• Supports a 2-point and 3-point contact key matrix

[ladyada]

its better to use a common digitalio-using API than a special peripheral

[dhalbert]

Closing this because we have keypad support.