Add support for MyMakers RP2350B board #3049

Job	Run time
Spelling, Style, Boards, Package, PIO	18s
Build 3	8m 33s
Build 2	8m 15s
Build 0	6m 20s
Build 1	7m 17s
Build 4	7m 10s
Build RP2350 1	6m 21s
Build 5	6m 25s
Build RP2350 0	6m 31s
Build RP2350 5	6m 5s
Build RP2350 2	7m 23s
Build RP2350 3	6m 48s
Build RP2350 4	6m 56s
Windows	3m 7s
Build PlatformIO Examples	3m 48s
Mac (macOS-13)	4m 45s
Mac (macOS-14)	2m 37s
Build Every Variant 1	1m 38s
Build TinyUSB Examples	4m 1s
Build Every Variant 2	1s
Build Every Variant 3	1m 7s
Build RP2350-RISCV 0	5m 34s
Build RP2350-RISCV 2	7m 2s
Build RP2350-RISCV 3	7m 31s
Build RP2350-RISCV 1	5m 57s
Build RP2350-RISCV 4	6m 28s
Build RP2350-RISCV 5	6m 3s
Build Every Variant 0	14m 7s
	2h 38m 8s

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