[PATCH 4.15 063/128] mtd: nand: ifc: update bufnum mask for ver >= 2.0.0

4.15-stable review patch. If anyone has any objections, please let me know. -- From: Jagdish Gediya [ Upstream commit bccb06c353af3764ca86d9da47652458e6c2eb41 ] Bufnum mask is used to calculate page position in the internal SRAM. As IFC version 2.0.0

[PATCH 4.15 063/128] mtd: nand: ifc: update bufnum mask for ver >= 2.0.0

4.15-stable review patch. If anyone has any objections, please let me know. -- From: Jagdish Gediya [ Upstream commit bccb06c353af3764ca86d9da47652458e6c2eb41 ] Bufnum mask is used to calculate page position in the internal SRAM. As IFC version 2.0.0 has 16KB of internal