nvmem: eeprom: at25: fix type compiler warnings

nvmem: eeprom: at25: fix type compiler warnings

Fixes:
	drivers/misc/eeprom/at25.c:181:28: warning: field width should have type 'int', but argument has type 'unsigned long'
	drivers/misc/eeprom/at25.c:386:13: warning: cast to smaller integer type 'int' from 'const void *'

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Jiri Prchal <jiri.prchal@aksignal.cz>
Fixes: fd307a4ad332 ("nvmem: prepare basics for FRAM support")
Link: https://lore.kernel.org/r/20210611142706.27336-1-jiri.prchal@aksignal.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>