Fix undefined behavior compile error

[Sh3Rm4n]

No description provided.

[adamgreig]

It looks like this changes the access of the data register from Word-sized (which I think might be u8 or u16?) to always be a 32-bit access. Annoyingly the data register is access-size-sensitive, and doing a 32-bit read can cause up to 4 8-bit words to be popped from the peripheral's FIFO. This is the same problem as stm32-rs/stm32f7xx-hal#207

[Sh3Rm4n]

Thanks for the info. This means, we currently can not read 8 or 16 bits from the data register through the svd2rust API, but casting is not the correct way either?