Ubuntu: (CVE-2021-47016): linux vulnerability

In the Linux kernel, the following vulnerability has been resolved:

m68k: mvme147,mvme16x: Don't wipe PCC timer config bits

Don't clear the timer 1 configuration bits when clearing the interrupt flag
and counter overflow. As Michael reported, "This results in no timer
interrupts being delivered after the first. Initialization then hangs
in calibrate_delay as the jiffies counter is not updated."

On mvme16x, enable the timer after requesting the irq, consistent with
mvme147.