tcl/target/rp2350: workarounds for ROM API issues

tcl/target/rp2350: workarounds for ROM API issues

A0 chip: remove pad isolation
A2 chip: instead of reset init fixes we will fix the flash driver
with the following patch by Luke Wren:
8729: flash/nor/rp2xxx: fix flash operation after halt in RISC-V bootsel
https://review.openocd.org/c/openocd/+/8729

I don't have A1 version to test.

Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Change-Id: I9e9fab04ead929fe6e0a17c6c2f32a6f02e9beb9
Reviewed-on: https://review.openocd.org/c/openocd/+/8450
Tested-by: jenkins