ARM: OMAP3+: SmartReflex: use only 24 bits of efuse for NVALUERECIPROCAL

NVALUERECIPROCAL is a 24 bit value, remaining bits may contain other
data. Even though the AVS IP block marks bits [31-24] as reserved for
all AVS IP blocks used since OMAP3430-OMAP5, it is safer to mask out
the remaining bits out.

Change-Id: I5e69d12afa7700cd59e66c0b9bfb1eba3740abad
Signed-off-by: Nishanth Menon <nm@ti.com>