Added K20D5M support
Merge branch 'master' into K20D50
K20 uVision files, ld NVIC offset

	- K20 KEIL files
	- clock set to 1 (48MHz)
	- offset in GCC ld for vectors in RAM
	- us ticker - PIT timer interrupt implementation
startup ARM - stack pointer, serial functional

	- stack pointer correction
	- startup for ARM - clean up
	- GCC ARM linker - RAM size correction
	- NVIC - RAM address
Analog API - pins, analog pins (arduino) correction, irq

	- ADC - pins, mux
	- analog pins - Ax
	- irq - port A - E
pwm, spi - pin definition, dac removed
Merge branch 'master' into K20D50
PWM - changes to start the channel
Merge branch 'master' into K20D50
SPI, RTC, Serial changes

	- SPI - implementation
	- RTC - there's 32.768kHz crystal, use that as a source
	- Serial - 10bit transfer
Merge branch 'master' into K20D50
I2C, pullup
LPTMR timer - OSCEN set, GCC startup vectors add
K20D5M exporters for uVision and ARM GCC
K20D5M flash algo for template
Merge branch 'master' into K20D50
K20D5M default irq handler
Merge pull request #135 from 0xc0170/K20D50

target K20D5M