rtc: pcf85063: fix potential OOB write in PCF85063 NVMEM read

In the Linux kernel, the following vulnerability has been resolved: rtc: pcf85063: fix potential OOB write in PCF85063 NVMEM read The nvmem interface supports variable buffer sizes, while the regmap interface operates with fixed-size storage. If an nvmem client uses a buffer size less than 4 bytes, regmap_read will write out of bounds as it expects the buffer to point at an unsigned int. Fix this by using an intermediary unsigned int to hold the value.