msm: mdss: Return error when Gamut table size is invalid

Previously, the gamut caching code was not returning an error value when
an invalid table size was passed. This change will return error during
caching if the table size is invalid.

Change-Id: I212b345239543943670c2f03a0fc8376d31d1e86
Signed-off-by: Benet Clark <benetc@codeaurora.org>