fs/resctrl: Remove the limit on the number of CLOSID

At the moment, number of resource control group (user can create) is
limited to 32. Remove the limit.

ffs() returns '1' for bit 0, hence the existing code subtracts 1 from
the index to get the CLOSID value. find_first_bit() returns the bit
number which does not need adjusting.

Signed-off-by: Amit Singh Tomar <amitsinght@marvell.com>
[ morse: fixed the off-by-one in the allocator and the wrong
  not-found value. Removed the limit. ]
Signed-off-by: James Morse <james.morse@arm.com>