samd/machine_uart: Fix unintended UART buffer allocation on init().

The buffer was be reset on every call to uart.init().  If no sizes were
given, the buffer was set to the default size 256.  That made problems
e.g. with PPP.

This commit fixes it, keeping the buffer size if not deliberately changed
and allocating new buffers only if the size was changed.  Cater for changes
of the bits value, which requires a change to the buffer size.

Signed-off-by: robert-hh <robert@hammelrath.com>

0 files changed, 0 insertions, 0 deletions