Apply the U suffix to unsigned integer literal constants used in
contexts involving unsigned types (uint8_t, uint16_t, uint32_t,
uint64_t, size_t, etc.) with coding guideline 40 which requires that
"A u or U suffix shall be applied to all integer constants that are
represented in an unsigned type".
In addition to this requirement, this commit also ads U to any unsigned
literal integer for the sake of completeness.
Changes are limited to literal values in assignments, initializations,
comparisons, and for-loop bounds where the context is unambiguously
unsigned.
Assisted-by: GitHub Copilot:claude-sonnet-4.6
Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>