[ARM] rpc: silence two section mismatch warnings

WARNING: drivers/built-in.o(.text+0x3fd54): Section mismatch: reference to .init.data: (between 'ether3_probe' and 'ether1_setmulticastlist')
WARNING: drivers/built-in.o(.text+0x40380): Section mismatch: reference to .init.data: (between 'ether1_probe' and 'ether1_interrupt')

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>